Towards Sustainable Mobility? The Inﬂuence of the COVID-19 Pandemic on Romanian Mobile Citizens in Spain

: Using the case study of Romanians in Spain, this article highlights how the COVID-19 crisis presents both challenges and opportunities when it comes to human mobility and sustainability. Drawing on in-depth interviews with mobile people during the period of lockdown and circulation restrictions, and in accordance with the objectives of the Sustainable Development Goals (SDGs), the paper advances and contributes to the relevance of sustainability and its impact on people’s mobility in the context of the COVID-19 pandemic. I argue that even in the midst of the crisis, sustainable ways may be found to promote and protect human mobility. The paper raises the way sustainability acts as a driver, gains relevance and inﬂuence, and contributes to the creation of new models of resilient mobility in times of crisis. The conclusions defend the respect for the SDGs regarding human mobility and emphasise the role of people on the move as sustainable actors learning to overcome distance and the barriers to their mobility during the pandemic.


Introduction
The COVID-19 pandemic is a public health, socioeconomic, political, and human rights crisis that has resulted in over 123 million cases and the death of over 2.7 million people and has severely impacted national economies worldwide [1]. The European Union (EU) is one of the regions of the world with greatest spread of the virus, and human mobility has played a central role. Spain, with a very high migration and mobility rate, is one of the focal points of the COVID-19 pandemic, both in terms of number of infections and deaths. Its dependence on tourism (one of the worst affected sectors) combines with the low technological base of its production model, the fragility of the labour market, the inequality inherited from the previous crisis (2008), and a prior level of public debt that conditions stimulus plans. In this framework, migration to Spain has become a real battlefield. Flows from Latin America, North Africa, and Eastern Europe are finding it increasingly difficult to find a place in the Spanish labour market. Among the Eastern European countries the country with the most mobile people is Romania, with over 5.6 million people scattered around the world. More than 1 million Romanians practice mobility between Spain and Romania.
Using the case study of Romanians in Spain, the contribution of this paper highlights how the COVID-19 crisis affects human mobility and sustainability in terms of challenges and opportunities. The paper thus advances and contributes to the relevance of sustainability and its impact on people's mobility in the context of the COVID-19 pandemic. It then goes on to address how sustainability could protect and promote human mobility. How does this pandemic crisis affect the circulation of Romanians? How have Romanians moved in an EU with locked-down borders? How does this crisis with dramatic economic effects affect their labour situation in Spain and their health and fear of contagion?
Utilising qualitative methodology and in accordance with the objectives of the Sustainable Development Goals (SDGs), this paper contributes to the knowledge on the sustainable Sustainability 2021, 13, 4023 2 of 18 mobility of the people. It raises the way the concept of sustainability gains relevance and contributes to the creation of new models of mobility in times of pandemic. Thus, the scientific contribution of this article focuses on the argument that in the context of the pandemic, an orderly labour and professional movement and return migration are helping to reconceptualise resilience and sustainable mobility in the 21st century.
To do so, this article engages with Sustainable Development Goal indicator (The Sustainable Development Agenda 2030) [2] 10.7.2 "Number of countries with migration policies to facilitate orderly, safe, regular and responsible migration and mobility of people". To what extent do the COVID-19 responses-whether mobility, crisis response, health, or other policies-address the special needs and vulnerabilities of mobile people and empower them to contribute to the COVID-19 response and to the economy?
First, the paper introduces Spain as one of the European countries worst affected by the pandemic, and the link between this and human mobility. Second, it explains a brief theoretical framework which connects human movement to the need to apply sustainable methods to labour mobility between countries. It then discusses the EU's borders during the lockdown period, and the subsequent stage of the pandemic with the closure, semi-opening, and opening of borders between Spain and Romania. After introducing the methodology, the article analyses high-risk labour mobility, highlighting mobility for agricultural tasks, for domestic and care services and for urgent return. Finally, the paper emphasises the future plans of the Romanians interviewed who advocate for a resilient return that favours the sustainable development of their country of origin.
It is necessary to point out that this research has limitations-being an original and innovative article, written in the midst of a pandemic, it has been difficult to find specific literature that links human mobility to the concept of sustainability in the COVID-19 period. It is therefore proposed as a starting point in the field of studies linking human mobility with sustainability in the COVID-19 era, which researchers may continue, using both qualitative and quantitative methodology.

Theoretical Framework: Human Mobility and Sustainability
The spread of COVID-19 and its worldwide presence-albeit with very uneven intensity-has starkly exposed some of the limits and risks of human hypermobility. Human mobility by air transport seems especially sensitive in this new context. In this context, the apparently unstoppable growth of tourism and of international labour mobility flows raises new questions about sustainability that include economic, environmental, and health dimensions.
The 2030 Agenda for Sustainable Development (2020) interconnects people, peace, planet, and prosperity. It seeks to facilitate orderly, safe, regular, and responsible migration and mobility of people including through the implementation of planned and well-managed migration policy. However, to date, research on global human mobility during pandemics is not contemplated and developed. Several authors have analysed the mobility of people in cities and the inclusion of refugees, stressing the need for changes and opportunities in cities related to mobility planning [3][4][5], particularly in terms of providing more segregated walking and cycling trails and routes.
Kraemer et al. analysed the effect of human mobility and control measures on the COVID-19 epidemic in China [6]. Wisdom and Kivimaa [7] explored the ramifications for sustainability transition research on electricity and mobility, drawing from selected examples in Finland and Sweden. They highlighted that the long-term consequences of the COVID-19 pandemic are likely to trigger permanent changes connected to the digitalisation of work and other daily activities, thereby reducing mobility needs and overall fossil-fuel consumption. Using two Italian cities, Palermo and Catania, before and during the pandemic, Moslem et al. [8] examined the transport sector with a specific focus on the problem of commuting mode choice and proposed a new decision-making approach for alternative modes of transport. Using public transport users in Gdansk, Przybylowski et al. [9] analysed mobility behaviour in view of the impact of the COVID-19.
Other authors [10][11][12][13] also examined the impact of the pandemic linked to the closure of borders and, in particular, the immobility of students in cities. Other authors [14][15][16], in turn, analysed the impact of COVID-19 on refugees' economic inclusion. Guy and Gietel-Bastel [17] briefly visualised international remittance flows and the economic and social consequences of the pandemic. Linked to this, Anderson et al. [18] noted that migrant workers could play an important role in the resilience of countries and sectors during times of crises.
However, the direct link between human mobility and sustainability in times of pandemic has not yet been studied. This is what this article tries to accomplish, taking into account that human mobility is a key factor for sustainable development.

Spain in the European Context of the COVID-19 Pandemic
The pandemic in Europe is part of the global COVID-19 pandemic caused by the SARS-CoV-2 coronavirus. The first cases in Europe appeared in France, Germany, and Italy, with a large outbreak emerging in northern Italy near Milan in February 2020. Cases grew rapidly and on 13 March 2020, and the World Health Organisation declared Europe to be the new epicentre of the virus after the situation had improved in China [19]. In Spain, the COVID-19 pandemic has caused 59,081 deaths (up until January 2021) ( Figure 1) and 2,082,000 cases confirmed by PCR ( Figure 2) [20]. alternative modes of transport. Using public transport users in Gdansk, Przybylowski et al. [9] analysed mobility behaviour in view of the impact of the COVID-19. Other authors [10][11][12][13] also examined the impact of the pandemic linked to the closure of borders and, in particular, the immobility of students in cities. Other authors [14][15][16], in turn, analysed the impact of COVID-19 on refugees' economic inclusion. Guy and Gietel-Bastel [17] briefly visualised international remittance flows and the economic and social consequences of the pandemic. Linked to this, Anderson et al. [18] noted that migrant workers could play an important role in the resilience of countries and sectors during times of crises. However, the direct link between human mobility and sustainability in times of pandemic has not yet been studied. This is what this article tries to accomplish, taking into account that human mobility is a key factor for sustainable development.

Spain in the European Context of the COVID-19 Pandemic
The pandemic in Europe is part of the global COVID-19 pandemic caused by the SARS-CoV-2 coronavirus. The first cases in Europe appeared in France, Germany, and Italy, with a large outbreak emerging in northern Italy near Milan in February 2020. Cases grew rapidly and on 13 March 2020, and the World Health Organisation declared Europe to be the new epicentre of the virus after the situation had improved in China [19]. In Spain, the COVID-19 pandemic has caused 59,081 deaths (up until January 2021) ( Figure  1) and 2,082,000 cases confirmed by PCR ( Figure 2) [20].   alternative modes of transport. Using public transport users in Gdansk, Przybylowski et al. [9] analysed mobility behaviour in view of the impact of the COVID-19. Other authors [10][11][12][13] also examined the impact of the pandemic linked to the closure of borders and, in particular, the immobility of students in cities. Other authors [14][15][16], in turn, analysed the impact of COVID-19 on refugees' economic inclusion. Guy and Gietel-Bastel [17] briefly visualised international remittance flows and the economic and social consequences of the pandemic. Linked to this, Anderson et al. [18] noted that migrant workers could play an important role in the resilience of countries and sectors during times of crises. However, the direct link between human mobility and sustainability in times of pandemic has not yet been studied. This is what this article tries to accomplish, taking into account that human mobility is a key factor for sustainable development.

Spain in the European Context of the COVID-19 Pandemic
The pandemic in Europe is part of the global COVID-19 pandemic caused by the SARS-CoV-2 coronavirus. The first cases in Europe appeared in France, Germany, and Italy, with a large outbreak emerging in northern Italy near Milan in February 2020. Cases grew rapidly and on 13 March 2020, and the World Health Organisation declared Europe to be the new epicentre of the virus after the situation had improved in China [19]. In Spain, the COVID-19 pandemic has caused 59,081 deaths (up until January 2021) ( Figure  1) and 2,082,000 cases confirmed by PCR ( Figure 2) [20].   Given the rapid spread of the virus, on March 14th 2020, a state of alarm was decreed throughout the country, the free movement of people was limited, and the population was confined to their places of residence. At the end of March, all non-essential face-toface work activities were suspended for 15 days. On April 2nd, the highest number of daily deaths from coronavirus was recorded (950). Successive extensions of the state of alarm were subsequently authorised up to a total of six times [21]. As of April 28th, the asymmetric de-escalation plan by province began. In mid-June, Spain had the fifth highest number of confirmed cases, behind the USA, Brazil, Russia, and Great Britain, and the sixth highest number of deaths, behind the United States, Brazil, the United Kingdom, Italy, and France [22]. On June 21st, after 98 days, the state of alarm expired, and Spain entered the so-called its "new normality". Throughout the summer, however, the outbreaks multiplied, could not be contained, and degenerated into community transmission. At the end of October, Spain exceeded 1 million infections and the government again decreed the state of alarm in order to face the second wave of infections. A night-time curfew was established until May 2021. On 27 December 2020, Spain's vaccination campaign began with the Pfizer BioNTech vaccine, a week after being approved by the European Medicines Agency and the European Commission. In January 2021, the milestone of two million infections was passed [23].
The pandemic crisis also seriously affected the Spanish economy, which suffered a collapse of 11% in 2020, according to the National Institute of Statistics [24]. One has to go back to the Spanish Civil War to find a similar contraction. Until now, the largest annual decline in GDP, recorded in 2009 in the midst of the financial crisis, was 3.8% (see [24]).
Consequently, the COVID-19 crisis dramatically affected human mobility. Due to the serious incidence of the disease, especially in the second and third waves, other EU countries-including Romania-kept Spain on the list of countries of high epidemiological risk [25].

EU Borders and Human Mobility between Spain and Romania during the Pandemic
Since the outbreak of COVID-19, the mobility restrictions imposed have been unprecedented on a local, regional, and global scale [26]. Between March and June 2020, EU countries have closed their borders and imposed stringent quarantine measures [27]. The COVID-19 pandemic has also shown that highly mobile workers who frequently move either within or in and out of the EU are irreplaceable during a public health crisis. Nevertheless, they often remain the least protected and most vulnerable groups [28]. One group of people continued to cross borders and thereby expose themselves to risk, often because they had hardly any other choice: migrant workers from Eastern Europe, especially Romanians. As mobile citizens, they make important contributions to addressing the pandemic but are also exposed to the risk of catching the virus. Thus, the persistent inequalities within the EU were exposed more clearly than ever.
Governments and businesses in Western Europe have pushed for travel exemptions for Eastern European countries (including Romania) in order to tackle the dire shortages of seasonal labour for planting and harvesting crops at this time of the year. On March 30th, the European Commission released new "practical advice" to ensure that cross-border and frontier workers within the EU, particularly those with critical professions, could reach their workplace [29]. The definition of "critical professions" is extremely flexible, "This includes those working in the healthcare and food sectors, and other essential services like childcare, elderly care, and critical staff for utilities" [30].
As expected, border closure announcements provoked desires to return to countries of origin out of fear of being stranded without income or access to social protection. The inability to return has resulted in large numbers of Romanian citizens being "trapped" in Spain. According to data from the Consular Service of the Romanian Embassy in Madrid (2020), more than 20% of Romanian workers moving between Spain and Romania during the pandemic work in the agricultural sector, 8% work in healthcare and social work, more than 7% in transportation services, and more than 10% in the accommodation and food industries [31].
In this context, it is important to note that research on population and development has proposed specific measures to provide assistance to citizens residing abroad in crisis situations. Hence, assistance to mobile citizens abroad should be a priority. The Spanish government, however, has had no strategy with specific measures to provide assistance to migrants and mobile citizens in the country before, during, and after the crisis phases in the country.
During the lockdown period, Romanian consular staff in Spain assisted and coordinated the return of nationals to Romania ( Figure 3). Spain. According to data from the Consular Service of the Romanian Embassy in Madrid (2020), more than 20% of Romanian workers moving between Spain and Romania during the pandemic work in the agricultural sector, 8% work in healthcare and social work, more than 7% in transportation services, and more than 10% in the accommodation and food industries [31]. In this context, it is important to note that research on population and development has proposed specific measures to provide assistance to citizens residing abroad in crisis situations. Hence, assistance to mobile citizens abroad should be a priority. The Spanish government, however, has had no strategy with specific measures to provide assistance to migrants and mobile citizens in the country before, during, and after the crisis phases in the country.
During the lockdown period, Romanian consular staff in Spain assisted and coordinated the return of nationals to Romania ( Figure 3). From March to May 2020, 3256 Romanians returned to their country on 19 flights, even while commercial flights were stopped [32]. One key reason behind the limited assistance to their nationals abroad could be that Romania lacks the financial and human resources to provide more assistance. Although many returned, other mobile citizens, including international students and migrant workers in the agricultural sector, were unable to do so. The charter flights left from Madrid and Barcelona, but also from Tenerife and Málaga. Above all, those who returned were seasonal workers, but tourists were also stuck in Spain in the first phase of the crisis, along with Erasmus students and elderly people who had come to visit their children or to care for their grandchildren. Other Romanians returned in their own cars, after intervention by the Romanian Embassy to secure schedules and special transit corridors in Germany, Austria, and Hungary.
With the borders closed, hundreds of seasonal workers-discontinuous permanent workers-from Romania managed to take part in seasonal agricultural work in various regions of the country (Aragon, Andalusia, Extremadura) with the reactivation of flights between Spain and Romania.
On 15 June 2020, the European Commission launched "Re-open EU", an online platform that contains essential information about the safe relaunch of free movement and tourism across Europe. It provides information on borders, available means of transport, travel restrictions, public health, and safety measures, such as physical distancing or wearing of facemasks, and other practical information for travellers [33].
After the end of the lockdown, from June to December 2020, Spain kept its borders open with Romania, precisely to facilitate the mobility of Romanian citizens between the two countries. Upon arriving in Romania, all were obliged to quarantine for 14 days because, coming from Spain, they were seen as a serious risk of infection (see document From March to May 2020, 3256 Romanians returned to their country on 19 flights, even while commercial flights were stopped [32]. One key reason behind the limited assistance to their nationals abroad could be that Romania lacks the financial and human resources to provide more assistance. Although many returned, other mobile citizens, including international students and migrant workers in the agricultural sector, were unable to do so. The charter flights left from Madrid and Barcelona, but also from Tenerife and Málaga. Above all, those who returned were seasonal workers, but tourists were also stuck in Spain in the first phase of the crisis, along with Erasmus students and elderly people who had come to visit their children or to care for their grandchildren. Other Romanians returned in their own cars, after intervention by the Romanian Embassy to secure schedules and special transit corridors in Germany, Austria, and Hungary. With the borders closed, hundreds of seasonal workers-discontinuous permanent workers-from Romania managed to take part in seasonal agricultural work in various regions of the country (Aragon, Andalusia, Extremadura) with the reactivation of flights between Spain and Romania.
On 15 June 2020, the European Commission launched "Re-open EU", an online platform that contains essential information about the safe relaunch of free movement and tourism across Europe. It provides information on borders, available means of transport, travel restrictions, public health, and safety measures, such as physical distancing or wearing of facemasks, and other practical information for travellers [33].
After the end of the lockdown, from June to December 2020, Spain kept its borders open with Romania, precisely to facilitate the mobility of Romanian citizens between the two countries. Upon arriving in Romania, all were obliged to quarantine for 14 days because, coming from Spain, they were seen as a serious risk of infection (see document cited). As the level of contagion also increased in Romania (324,094 cases confirmed since the beginning of the pandemic) from mid-November [34], Spain included Romania in the list of countries whose mobile citizens needed to show a negative PCR test when arriving in Spanish territory. This measure greatly affects the mobility of Romanian citizens in Spain and has consequences for human mobility as a concept in the COVID-19 crisis setting. The number of infections in Romania is still low, in part due to the quick introduction of restrictive "social distancing" measures. However, any potential increase could be fatal given the austerity-stricken state of the country's health systems.

Romanians in Spain
Romanians represent the largest group of foreigners in Spain. After Romania's entry into the EU in 2007, their numbers increased to 1,074,868, according to the Ministry of Inclusion, Social Security and Migration [35]. These migrants come from all regions of Romania ( Figure 4) [29], and in Spain they are located above all in the Community of Madrid   However, only 215,000 Romanians were registered in the Spanish social security system in 2020-approximately 65,000 working in the agricultural system, 30,000 working in the domestic and care service, and around another 40,000 being self-employed; 597,694 were of undetermined residence, and 5582 were students. The unemployed numbered 84,437 people. During the lockdown, predictably, Romanian unemployment in Spain increased by more than 15%-a decline that was reflected in the lower number of contributors to the Spanish social security system in April (12,000 less than in March) [37]. According to INE statistics (2020) the number of Romanians arriving in Spain fell in 2019 to 27,011 people, while 35,832 citizens left [38]. The negative balance shows, on the one hand, that Romanian mobility is increasing, and on the other, that a significant number of people return to their country, or at least try to. However, only 215,000 Romanians were registered in the Spanish social security system in 2020-approximately 65,000 working in the agricultural system, 30,000 working in the domestic and care service, and around another 40,000 being self-employed; 597,694 were of undetermined residence, and 5582 were students. The unemployed numbered 84,437 people. During the lockdown, predictably, Romanian unemployment in Spain increased by more than 15%-a decline that was reflected in the lower number of contributors to the Spanish social security system in April (12,000 less than in March) [37]. According to INE statistics (2020) the number of Romanians arriving in Spain fell in 2019 to 27,011 people, while 35,832 citizens left [38]. The negative balance shows, on the one hand, that Romanian mobility is increasing, and on the other, that a significant number of people return to their country, or at least try to.
During this pandemic, the highly mobile Romanian workers in the irregular market bore the brunt of the crisis in multiple sectors, without receiving adequate protection. Highly mobile workers-and also the whole of the Romanian community in Spain-faced challenges related to border closures, job losses, a lack of aid and subsidies from the state, and health and safety in the workplace. This set of factors seriously affected the living conditions of the Romanian community in Spain.

Methodology
The paper contributes to the relevance of sustainability and its impact on people's mobility in the context of the COVID-19 pandemic. A qualitative case study approach was adopted, using in-depth interviews. Between April 2020 and December 2020, I conducted 45 in-depth interviews with Romanians who practiced mobility both during the quarantine period (10) and, above all, from June (35). Given the grave and dramatic situation the whole society went through, and the impossibility of meeting the interviewees, I considered it appropriate to conduct the interviews online via Zoom after making contact During this pandemic, the highly mobile Romanian workers in the irregular market bore the brunt of the crisis in multiple sectors, without receiving adequate protection. Highly mobile workers-and also the whole of the Romanian community in Spain-faced challenges related to border closures, job losses, a lack of aid and subsidies from the state, and health and safety in the workplace. This set of factors seriously affected the living conditions of the Romanian community in Spain.

Methodology
The paper contributes to the relevance of sustainability and its impact on people's mobility in the context of the COVID-19 pandemic. A qualitative case study approach was adopted, using in-depth interviews. Between April 2020 and December 2020, I conducted 45 in-depth interviews with Romanians who practiced mobility both during the quarantine period (10) and, above all, from June (35). Given the grave and dramatic situation the whole society went through, and the impossibility of meeting the interviewees, I considered it appropriate to conduct the interviews online via Zoom after making contact through the most commonly used social networks. To carry out the search, I used the snowball technique, starting with the contacts I already had and continuing with the search for new contacts through Facebook, Twitter, and Instagram. I interviewed 20 men and 25 women of working age, 15 agricultural workers, 15 workers in the care and domestic service sectors, 7 people with their own businesses, and 2 people who worked in the hospitality sector and lost their jobs. The respondents were married, and more than half of them had families in Romania. I also interviewed 6 students, 3 of whom practiced mobility, and 3 of whom returned to Romania. The interviews were conducted in Romanian and lasted about 40 min. The questions put to the interviewees covered distinct areas. First, participants were asked to provide a brief account of their family and background before/after their move and their mobility to/from Spain. Second, we discussed their experiences of mobility during the pandemic, the factors that triggered their mobility during lockdown periods and throughout the year, and whether they were afraid of the risks of infection. Similarly, respondents were asked if they faced obstacles at the borders, and to describe how the pandemic changed their normal mobility patterns. Similarly, respondents were asked if they faced obstacles at the borders, and to describe how the pandemic changed their normal mobility patterns. They were asked to describe the mobility process itself, and the socio-sanitary measures they had to take, whether the PCR tests were performed before and after the trip, and whether they had to pass quarantine periods in both countries. Finally, they were asked to talk about how they saw their professional future and whether they had plans to return to their country.
It is important to highlight the difficulty and limitations of carrying out fieldwork in pandemic conditions-first, to find people to grant an interview in the middle of the pandemic, and second, because the interviews were conducted at very difficult times when most of the interviewees were risking their lives. In this article, the interviewees were given pseudonyms to preserve their anonymity. I transcribed and translated the interviews, and then coded and analysed them using the qualitative data analysis software Atlas.ti (Version 7.0). The analysis of the information from the standpoint of codes, concepts, and categories identified key relations between the data obtained and conclusions reached [39].

Analysis: Human Mobility and Sustainability in Times of Pandemic
In what follows, I provide an analysis of my findings in relation to three key themes that together characterise the presence of human mobility and sustainability in times of pandemic: unsustainable, high-risk labour mobility; urgent return; and resilient, sustainable mobility.

Unsustainable, High-Risk Labour Mobility
The COVID-19 pandemic highlighted the powerful role of government and the influence of its decision-making capacity on the practices of individuals, communities, and businesses (OECD, 2020) [40]. It is this capacity that has reduced international human mobility through border closures and travel restrictions of unprecedented scale. The human mobility targets of the 2030 Agenda for Sustainable Development were effectively suspended. The most explicit of these is target 10.7, which calls on countries to facilitate orderly, safe, regular, and responsible mobility of people, including through the implementation of planned and well-managed migration policies. Other migration-related targets in the 2030 Agenda include, among others, decent work, respecting the labour rights of migrant workers, and reducing the costs of transferring remittances.
In Spain, during the first and second waves of the pandemic, many Romanians engaged in mobility after losing their jobs. More than half of the interviewees who worked under contract took advantage of the temporary redundancy plan, (ERTE) which consists of the company adopting a temporary suspension of the employment relationship with a specific section of its workers. Two types of ERTE were established in Spain: (1) suspension of employment, and (2) a reduction in working hours in the event that the dismissal of workers was not necessary. All my respondents working under contract indicated that they were eligible for ERTE type 1-suspension of employment for economic, technical, organisational, or production reasons [41]. Specifically, Romanians who practiced labour mobility in the context of the pandemic, both during quarantine and throughout the year, did so in conditions of high risk for their health, for the health of the staff and families of their workplace, and for that of their own families. During 2020, the need to move for work put their lives in danger.

Agricultural Sector
The agricultural sector was the most affected of all. The COVID-19 crisis has shown how dependent modern societies are on an agro-food industry that, in turn, largely depends Sustainability 2021, 13, 4023 9 of 18 on the yearly mobility of thousands of workers [42]. During the quarantine, some of the Romanians living in Spain worked without a contract, while many-more than 40%-came from their home country with a "contract in origin". During the quarantine, seasonal farm workers faced growing demand and difficult, even dangerous working conditions. By highlighting the fact that Spanish farming depends to a large extent on migrant labour, national farming associations have raised the alarm about wide-scale labour shortages, especially with respect to the labour force from Romania as a consequence of border lockdowns. According to official data, around 50,000-70,000 seasonal Romanian workers could not work in 2020 (see [37]). A high percentage of food production on Spanish land relies on the labour of these migrant workers, especially Romanians, who constitute the largest group of agricultural workers in Spain.
The degrading living conditions of migrant farmworkers, especially in southern Spain, raise even more concerns during a pandemic.
Indeed, many migrant workers live in isolated and crowded outbuildings, in tent cities, or in slums, without essential services such as access to water and sanitation. In such places, the spread of the virus can have dramatic effects. During the lockdown between March and June, Romanian seasonal workers in the agricultural sector (e.g., picking asparagus and strawberries) suffered numerous cases of exploitation (low wages, lack of medical insurance, inhumane living conditions).
The Romanian Ambassador visited the rural places where they worked and, alongside the labour delegates from the region and the Spanish government, intervened to improve their living conditions. A prevention guide was drawn up [43].
The fieldwork carried out for this research showed that many of the Romanians coming to work in agriculture in Spain on temporary contracts stayed on to live in the country and lost their jobs as a result of the pandemic. Others had to return. Some continued to work without protection in the Spanish fields. However, there were cases of interviewees coming from Romania to work in agriculture without any protection, I arrived from Romania to pick asparagus mid-quarantine . . . At the airport, they only took my temperature and let me pass. However, when I arrived at the Aranjuez camp, they did not hire me, they said that they were afraid I would infect them. After fourteen days of quarantine, yes, I was able to work, but I lost a lot of money that my family needed. (Male, 45 years old) However, the worst-affected workers were those who had to practice mobility between Romania and Spain for the strawberry harvest season. For them, mobility was (un)sustainable.
Constantine, one of the Romanian temporary workers, said, I had to travel to Spain, to Segovia, for the strawberry harvest. The quarantine period and afterwards that I had to pass when arriving in Spain prevented us from traveling. It was the daily bread for my family. This was a lost year for us . . .

. (Woman, 48 years old)
Romania is the main source of seasonal workers in the strawberry sector, and between April and September, mobility was highly risky for Romanians [44]. Segovia is one of the most important strawberry cultivation areas in the world, and during 2020, the strawberry harvest could not be carried out properly because the mobility of seasonal workers was unsustainable. The high risk posed by their mobility (that Romanian temporary workers might bring the coronavirus to Segovia) meant that they were not allowed to travel to Spain. Romanian women were the only solution, but very few took risks. This led to the ruin of many companies in the region.

Domestic and Care Sector
Another key sector for the migrant economy with direct implications in this pandemic was and is the domestic service and care sector. The people involved, mostly women, have suffered and continue to suffer occupational risk and unsustainable mobility.
Since the 1990s, Spain has addressed the inadequacies of its family-based welfare and care system by outsourcing care work to migrant workers, especially women from eastern EU countries (particularly Romania). According to official data in 2020, over 70% of registered domestic workers were foreigners (and 45% were Romanian women) [45].
However, many of these women work in the elderly care sector with contracts in both countries of origin and destination, meaning they practice circular mobility-two weeks in Spain, and another two in Romania. They are members of the same family who take turns. The pandemic has disrupted their lives, as many of them lost their jobs in the elderly residence homes where they worked. Closed borders further complicated their situation.
Romanian women working on contracts in the healthcare sector, such as nurses in home hospitals and those practicing circular mobility (two weeks in Spain, two more in Romania), were also affected during the pandemic. They were indispensable during the pandemic and were in fact frontier workers who were among the first affected by borders being partially closed. At the end of the border closure, they were the first to continue their activity, despite the enormous risks of infection.
María told me I took a risk, even at the end of lockdown. I was one of the people who kept working, and they allowed me to catch a plane in May and travel to Romania to see my daughter. This interview highlights the lack of attention given to foreigners, in this case Romanians working in Spain on temporary contracts, despite the pandemic affecting their lives at all levels due to difficult and unsustainable mobility.
However, women working irregularly were most affected [46]. The interviewees' work in the informal sector had negative effects on income, working time, safety, and occupational health, in addition to the very difficult working conditions. During the lockdown, however, their incomes were reduced to zero.
Romanian domestic workers have increasingly replaced unpaid care by local women, "accepting" work under substandard and exploitative conditions. While exploitation mainly consists of excessive working hours and low salaries, it can often involve more subtle and severe forms of abuse. In the current health emergency, it has become difficult for many Romanian domestic workers, especially those without a residence permit or a regular contract, to go to a family's house to provide care and housework. Moreover, providing domestic and care support has become risky for both the workers and the recipients in terms of the risk of infection from the COVID-19 virus.
The interviews show that working without a contract has had serious repercussions on women's lives.
Simona said I lost my job because I was caring for an older lady. I had no employment contract. I was practically thrown out into the street. I waited throughout the entire lockdown at a friend's house, so that I could finally catch a plane and return to Romania. I think I will practice less mobility and travel to Spain only if someone gives me a contract. In the meantime, I will take care of my house and my own mother who is alone in my village.
(Woman, 53 years old) As for live-in domestic workers, many lost their jobs and, in turn, their housing as a consequence of the crisis provoked by the pandemic, and due to the high mortality rate among elderly people. This seems to be particularly dramatic in Madrid city, which is the worst hit by the pandemic and has the highest number of Romanian domestic workers.
Vanina told me The old lady I was caring for died, and although I had papers, they were of no use to me. I can't find a job . . . I lost my working rights because my contract ended due to the lady's death. And I couldn't move back to Romania until August, when I found a cheap flight. I ran out of savings; I will not return to Spain so soon. I'm afraid I no longer trust the EU... (Woman, 39 years old) The interview highlights the lack of protection for employees in the domestic and care service, the social unsustainability to which they are led. The pandemic crisis thus lays bare their precarious situation in Spain. Freedom of movement has been transformed into mobility for survival, although, in fact, this privilege is reserved for people in the physical condition to do so.
Workers in Eastern Europe (in this case Romanians) who take planes to work in countries such as Spain (but also Germany, Austria, and Italy) cannot trust either their own country or the European Union. This raises difficult questions about what eastern Europeans, and in this case Romanians, can expect after 14 years of EU membership.
On the basis of these considerations, and given the importance of care work, especially in a health emergency, it seems paradoxical that the Spanish government's financial support package for crisis-affected workers does not cover domestic workers. Furthermore, the current migrant regularisation proposal does not apply to migrant domestic workers in an irregular situation. The movement of people therefore needs rethinking, and a European debate should be generated on the Eastern European citizens who are doing essential and undervalued work, crossing borders amid the lockdowns, quarantines, and crises provoked by the COVID-19 pandemic.

Urgent Return Mobility
The 2030 Agenda also includes the provision of scholarships for study abroad (Target 4.b); respect for the labour rights of migrant workers (Target 8.8); reducing the costs of transferring remittances (Target 10.c); ending human trafficking (Targets 5.2, 8.7 and 16.2); and disaggregating data by various characteristics, including migratory status (Target 17.18) (see [2]). Nonetheless, the COVID-19 crisis has highlighted people's difficulty travelling urgently to their country of origin, both during lockdown and throughout 2020. In the specific case of Romanians with a high degree of mobility, the lockdown period was a crisis suffered by the whole community-from Erasmus students who had to return, to older people who were in Spain to take care of their grandchildren, and tourists who were passing through. All of them were trapped in Spain, and each had a different story of survival.
As noted above, the Romanian Embassy supported the urgent return of these citizens, although many were unable to take advantage of this assistance.
Adina said I was in Madrid at the Complutense University with an Erasmus scholarship. I could not find a place on a flight organized by the Romanian Embassy. So, I had to go back in a car with some friends. It was very difficult because we were stopped at every border. I didn't have a mask and when I entered Romania, they wouldn't let me in. It was like an endless nightmare. I was at the border for two days in Timisoara, and finally, I got home, where I was in solitary confinement for two weeks.

(Woman, 22 years old)
This interview highlights the difficulty young university scholarship holders faced in returning to their country, but there were also Romanians who lost their right to fly even if they had bought the tickets in advance, I came to Spain to take care of my granddaughter. I did not plan to stay in Spain, and when the lockdown began, and my daughter and her husband stayed at home, I got scared and bought a plane ticket. I wanted to go back to Romania with my husband, but there was no return flight and I stayed in Madrid until June, when the lockdown ended. It was a dramatic experience, mostly because my daughter lost her job, and we all had to return to Romania. (Woman, 69 years old) Meanwhile, Dumitru struggled to find flights, I was working in a cafe, but the owner closed and I lost my job. He had to return home. So, I did, but late, and with little savings, because I didn't find any flights until mid-July. (Man, 52 years old) All these cases show how unsustainable emerging mobility became during lockdown and throughout 2020 for mobile citizens. The interviews highlight the most negative aspects of mobility, especially in the case of the fragile and vulnerable people in precarious situations. According to statistical data (National Institute of Statistics Spain, 2020), 20% of Romanians living in Spain in the year 2020 were forced to leave the country due to their inability to survive (see [38]). Most returned to Romania in the second half of 2020.
It is important to note that in the context of the pandemic there was really no incentive from the Romanian authorities for their citizens to return to the country, even if they needed to for personal and/or family reasons.
The Ministry of Foreign Affairs constantly warned that mobility posed a major risk to citizens' security and to safe return to the country [47]. Recommendations were given to respect Spanish legislation and avoid displacements, but without offering alternatives for the people who were really affected-those who found themselves with no role or found it impossible to pay the rent in Spain. The ministry alleged that the return of Romanians to their country could be a risk factor for spreading COVID-19 that could endanger the security of the country's citizens.
Consequently, mobile Romanian citizens who returned during the year 2020 were, on the one hand, faced with long waiting periods at the borders, at the entrance to Romania, and (in addition to the quarantine periods they had to go through) on their return from Spain but, above all, they faced a degree of rejection from the Romanian population, who began to view them with suspicion.
Daniel said Daniel's return shows another human mobility difficulty experienced in a crisis environment. Romania is not prepared at the developmental, social, or mental levels to receive the population that has worked for years in other countries. Entrepreneurs who had successful careers in Spain and around the world are welcomed in order to support the country's development. However, it is necessary to create a strategy that relaunches emerging mobility, transforming it into resilient and sustainable return mobility.

Resilient and Sustainable Return Mobility
The resilience and the mobilisation of adaptive capabilities have been addressed in organisational studies relating to sustainable transitions, which offer a glimpse of recovery responses. Several factors must be addressed that are in line with the Sustainable Development Goals of the 2030 Agenda in order to achieve resilient and sustainable return mobility. One is reducing the proportion of unemployed people (especially young people) who lack the necessary training. Sustainability in human mobility means that it must be fair and necessary. First of all, therefore, Romania must invest more in returnees who lack the capacity to retrain with the resources acquired abroad.

Investing in Returnees
To date, most movement between Romania and Spain is seasonal and temporary. As a result, the return and reintegration of workers to their country is crucial. The EU supports return programmes that involve pre-departure, post-departure, and returnee support to maximise the development benefits of labour mobility. While away, movers can also access platforms to support Recognition of Prior Learning schemes so they know what types of work they can be connected to when they return. One example is the project "Home Plus-Entrepreneurs for Sustainability", ID 107821, co-financed by the Human Capital Operational Program 2014-2020 [48]. The objective of the project was the creation of new businesses in Romania with a non-agricultural profile in the urban environment (except Bucharest). Thus, as a result of the return of mobile citizens from Spain, more than 1000 businesses were created in tourism and construction and about 2500 jobs, which had a positive effect on the business sector in Romania and the standard of living of the Romanian population. COVID-19, however, affected these efforts. Furthermore, not all sectors of activity are receiving support. For example, women who work in the care sector and the most vulnerable people who return do not receive any kind of support. In the fieldwork, interviewees noted the lack of information for returnees.
Luminita said As noted, COVID-19 has already brought border closures throughout Europe, putting labour mobility programs on hold. Investment in necessary skills will be even more critical for the recovery, but the constrained economic environment will make such investments more difficult. Therefore, how should both Romania and Spain respond to the impact of COVID-19, and prepare their trainees for the post-COVID world? In this context, investment should be made in digital training. Romania needs to develop short courses to prepare people for their return, training people in digital literacy skills to make them ready for further training and the working environment, as well as to increase resilience.

Resilience and Re-Training for Romanians Who Lose Their Jobs
Resilience is the ability of a system to react to disruption, internal failures, and environmental events by absorbing the shock and/or reorganising to maintain its functions. The concept now includes the ability to face and adapt to change. This proactive perspective focuses on the capacity of a complex system to adapt to change by renewal and reorganisation and to find a new state of equilibrium.
In my research, I found people willing to start over in their home country, Romania, if they have the opportunity to do so.
Ciprian told me, I worked in a bar in Spain, and . . . with the pandemic, it closed. I lost my job, and now I have returned to Romania. I want to start over. I worked in Spain for ten years. And even though I didn't earn much, I have some money saved. And I will return to Spain only if the crisis passes. I also built my own house in Romania. Now I plan to start over in the tourism or agriculture sector, because I live in a tourist region. (Man, 39 years old) Several factors are notable in this quote. First, the mobile returnee has the capacity for resilience in the face of stressful life circumstances, using their capacities and resources to return to their country and work in other sectors of activity. Second, the mobility practiced in the last decade has allowed them to build a house in their country of origin. Finally, their mobility will become more sustainable because they will return to Spain only when necessary.
Tourism and agriculture are a significant contributor to development both in Spain and Romania. As in other parts of the globe, COVID-19 has devastated the industry both in Romania and migrant destination markets such as Spain, creating significant migrant job losses. In this challenging context the Romanian government must focus on re-training those who have lost their jobs due to COVID-19, ensuring they have the skills to contribute to the post-COVID-19 recovery.
As well as tourism, the agricultural, domestic, and care for the elderly sectors need to be strengthened. It has been noted that people were working in subhuman conditions without a legal framework to protect them. The pandemic has shown that for these people to return to their country or continue working in Spain with a contract of origin, a legal framework must be created for their mobility to be functional and sustainable.
Some of the young people interviewed indicated that they want to return to Romania, but if they cannot find a job, they are interested in attempting mobility to other regions of the globe, such as Australia or the Gulf states.
Victor said I have practiced mobility for a long time, with scholarships and for work. I would not mind practicing another type of mobility in the future, perhaps to move around less and settle in another country and return to work in my field. I am a biochemist, and I could contribute with my knowledge, contribute to the sustainability of the planet, and move around only when I need to. Maybe I'll go to Australia or Saudi Arabia. (Man, 32 years old) The pandemic has led people to reflect on their mobility. Moving less, but with clear and specific purposes can help contribute to the planet's sustainability. An awareness is thus shown of the global predicament and the need to become sustainable actors in their own mobility process.
Other interviewees were aware of the risks they have taken through their mobility during the pandemic.
In this vein, Tudorica explained I will return to Spain to pick strawberries only if a framework is established to revise my contract and they assure me that I can travel and risks are controlled, so that I don't arrive in Spain and have people afraid that I will bring them COVID. Working safely in the 2021 season . . . (Woman, 45 years old) Respondents thus demand a safe and sustainable framework to be able to continue practicing mobility to Spain. Consequently, a post-COVID-19 response to demand is needed. In addition, the Romanian government needs to work closely with the Spanish government to understand what skills Spanish businesses demand and tailor training accordingly. There is now a push for more elderly care workers and other health professionals to respond to the health implications of COVID-19, now and in the future. They are increasing elderly care training, while monitoring other-including new-skill demands.

Conclusions
This paper analysed how the pandemic crisis has affected human mobility and sustainability in terms of challenges and opportunity. Using the case study of Romanians in Spain during the lockdown and restrictions on circulation, and in accordance with the objectives of the sustainable development strategy, the paper highlights how despite the pandemic crisis, a sustainable approach can help protect and promote human mobility.
To answer the research question, I underline that COVID-19 affected the free movement of Romanians between Romania and Spain and had significant negative effects on the economic reasons for their mobility, as well as on the wider economy and their health. This paper engaged with article SDG indicator 10.7.2 "Number of countries with migration policies to facilitate orderly, safe, regular and responsible migration and mobility of people" (see [2]). The paper concludes that the COVID-19 response policies thus far fail to address the special needs and vulnerabilities of mobile people and do not empower them to contribute to the COVID-19 response or to the economy. It is therefore necessary to strengthen the link between human mobility and the concept of sustainability.
For sustainable mobility to be achieved in times of pandemic, it is crucial to harmonise three core elements: the development and economic growth of countries, social inclusion, and environmental protection. These elements are interconnected, and all are crucial for the well-being of individuals and societies. In this type of economic, social, and political climate, governments' migration politics are likely to remain restrictive. Temporary labour migration programmes and immigration points systems are particularly likely to proliferate. In the research carried out, it has been observed that the pandemic offers the opportunity to develop recovery plans that reverse current trends and redirect the modality of human mobility towards a more sustainable course.
In the specific case studied here, of mobile Romanians in Spain, it is first necessary to promote sustainable mobility between the two countries. Frameworks and agreements should be established that support sustainability in the main sectors affected by the pandemic the agricultural sector and the care sector, in such a way that mobility becomes fluid and sustainable and protects the health of workers [49]. It has been observed that governments, including Spain's, recommend that employers employ local workers. However, most of them prefer migrant workers [50]. Consequently, it is important to rethink human mobility policies to ensure systemic resilience.
Despite being a fundamental aspect of human life that is necessary for the well-being and reproduction of society itself, domestic and care work is undervalued and not seen as a priority [51,52]. Regularisation of undocumented migrants in this field, as well as other sectors such as agriculture, is urgent and necessary in order to ensure migrants' access to healthcare services without discrimination. The COVID-19 emergency and all the issues the pandemic has laid bare and simultaneously exacerbated should induce profound changes to the approach to migration and social inclusion policies by taking human rights seriously [53]. At the same time, since vulnerabilities are not only created by irregular status but stem from poverty, illiteracy, social exclusion, and discrimination-which are also widespread also among EU citizens-prevention of exploitation, first and foremost, requires respect for labour rights.
Second, it is essential that priority is given to the sustainable return of Romanians who lost their jobs due to the pandemic and need to start over in their country of origin or practice mobility to other countries that offer them opportunities for professional and personal development. Romania needs to strengthen its policies of reception and attraction of the mobile citizens that have spent many years and even decades outside the country. The experience they have acquired abroad, in this case in Spain, can help strengthen the country's production and business system, as well as agriculture and tourism [44]. Sustainable and necessary mobility must be encouraged in this way. The work done for this article highlights that through their mobility Romanians are able to become resilient actors for sustainable mobility. They are thus sustainable actors who despite distance and barriers learn to overcome the pandemic through their mobility [54,55].
Third, the pandemic not only jeopardised the prospects of promoting the implementation of the SDGs set out in the 2030 Agenda for Sustainable Development but also threatened to reverse the progress achieved to date and further exacerbate existing challenges and vulnerabilities in all areas. When joining forces to find measures to respond to the pandemic, it is fundamental that political actors, in this case both Romania and Spain, take advantage of the opportunity provided by this crisis to continue their efforts towards achieving the SDGs and through their implementation create more resilient societies and respond better to future crises. In line with previous discussions of the dialogue on the follow-up and review of the SDGs related to human mobility, it will be important to promote greater cooperation and create networks for future actions on migration governance and the achievement of the SDGs in the era that follows the pandemic [12]. It should be emphasised that the contributions of mobile citizens will be essential to achieving the SDGs during the period of recovery from the effects of the pandemic. It is also important to examine how the pandemic impacts the economic contributions of mobile citizens and how they could be safeguarded in the future [56].
Finally, it is essential to recognise human mobility as a prominent driver of the recovery post-COVID-19 [57]; to propose a change of discourse to combat discrimination and xenophobia in both destination countries and countries of origin in order to promote social cohesion and resilience through inclusion; to protect mobile citizens at increased risk from the pandemic [58]; to mitigate the effects of economic hardship experienced by mobile citizens and returnees; and to strengthen cooperation through the Global Compact for Safe, Orderly and Regular Migration, while respecting the Sustainable Development Goals.