Exploring the Potential of European Brown Shrimp (Crangon crangon) in Integrated Multi-Trophic Aquaculture: Towards Achieving Sustainable and Diversified Coastal Systems

Abstract

Global marine coastal aquaculture increased by 6.7 million tons in 2024, with whiteleg shrimp (Penaeus vannamei) dominating crustacean production. However, reliance on a single species raises sustainability concerns, particularly in the face of climate change. Diversifying shrimp farming by cultivating native species, such as the European brown shrimp (Crangon crangon), presents an opportunity to develop a sustainable blue bioeconomy in Europe. C. crangon holds significant commercial value, yet overexploitation has led to population declines. Integrated Multi-Trophic Aquaculture (IMTA) offers a viable solution by utilizing fish farm wastewater as a nutrient source, reducing both costs and environmental impact. Research efforts in Germany and other European nations are exploring IMTA’s potential by co-culturing shrimp with species like sea bream, sea bass, and salmon. The physiological adaptability and omnivorous diet of C. crangon further support its viability in aquaculture. However, critical knowledge gaps remain regarding its lipid metabolism, early ontogeny, and reproductive biology—factors essential for optimizing captive breeding. Future interdisciplinary research should refine larval culture techniques and develop sustainable co-culture models. Expanding C. crangon aquaculture aligns with the UN’s Sustainable Development Goals by enhancing food security, ecosystem resilience, and economic stability while reducing Europe’s reliance on seafood imports.

1. Introduction

In 2024, global marine coastal aquaculture production increased by 6.7 million tons (Mt), with crustaceans accounting for 1.6 Mt (24%) of this growth. Whiteleg shrimp (Penaeus vannamei), predominantly farmed in tropical and subtropical regions, currently represents 60% of total crustacean production [1]. This dependence on a single shrimp species for crustacean aquaculture production is particularly worrying under the current scenario of climate change (i.e., increased sea temperatures and acidification, extreme and unpredictable weather events, drastic changes in productivity and circulation patterns), which could negatively impact coastal aquaculture production [2,3]. Furthermore, in many shrimp-producing countries, the road to greater sustainability is still long. It is therefore urgent to diversify marine shrimp farming, particularly by adjusting which species are produced in which regions and to promote the cultivation of native species with commercial and economic potential [1]. In turn, most of the growing demand for blue foods (organisms harvested from marine environments) in Europe is currently being supplied by imports from abroad that are often of questionable quality [1]. The blue food production within Europe does not only not meet the current demand but European fisheries are also overexploited [1]. European aquaculture could therefore provide a safe, healthy, and sustainable food source for the local population [1].

1.1. The European Brown Shrimp Crangon crangon

The model species of this research perspective, the brown shrimp C. crangon, has great commercial value [4]. Over the last ten years, more than 30,000 tons have landed per year, with profits of up to EUR 100 million [4]. Currently, there is a greater demand for fresh and large shrimp (>70 mm), whose sale value is between 20% and 30% higher than that of cooked shrimp [5]. Considering (i) the high fishing pressure on this resource (overexploited) and the negative impact this has on coastal ecosystems [4,6], (ii) the drastic decline in its natural populations [4,6], and (iii) its currently growing demand and high commercial value (i.e., EUR 100 per kg) [4,5], this research perspective postulates that this native shrimp species is an ideal candidate for the diversification of the aquaculture industry in Europe, further advancing our goal to achieve a sustainable and blue bioeconomy [7,8]. However, the large-scale commercial cultivation of C. crangon in aquaculture will only become a viable new industry in the long term if a clear economic benefit for the aquaculture farmer is evident. To this end, it is crucial that production costs are kept as low as possible to ensure a high enough investment return.

1.2. Integrated Multi-Trophic Aquaculture (IMTA)

Considering environmental sustainability, including feasible solution by utilizing fish farm wastewater as a nutrient source, reducing both costs and ecological impact, the Integrated Multi-Trophic Aquaculture (IMTA, for concept see [9] and next paragraph) and also the co-culture of C. crangon with commercially important fish species (e.g., sea bream, sea bass, salmon, and trout, among others [10,11]) will have significant commercial and environmental benefits [9,12]. Particularly, wastewater from the aquaculture of these fish can be used as food (“Biowaste Diet”) for brown shrimp culture. Therefore, the co-culture of this species may offer an alternative to sustainably and consistently supply a niche market (large and fresh shrimp). This approach supports the UN Sustainable Development Goals—particularly SDG 2 (Zero Hunger), SDG 12 (Responsible Consumption and Production), and SDG 14 (Life Below Water) [13]—and aligns with an interdisciplinary social, ecological, and environmental framework (see [14] for the concept).

The concept of IMTA is currently being explored at the Fraunhofer Institute for Applied Research in Germany and at coastal research institutes in Belgium, the Netherlands, Denmark, and Norway [15,16]. IMTA involves cultivating not only fish but also other aquatic organisms, such as algae and invertebrates (including mussels, worms, and shrimp), within the same water system [17]. By mimicking natural ecosystems, IMTA creates an artificial environment where all organisms benefit from each other. Algae and invertebrates absorb the nutrients introduced into the water by fish, promoting their own growth while simultaneously purifying the water. This process reduces nutrient loads in wastewater while increasing the production of usable biomass [18]. IMTA can be implemented in both marine and land-based systems, each presenting its own opportunities and challenges. On land, water quality must be carefully monitored and controlled, which enables optimized production [17]. Additionally, optimizing energy flows plays a crucial role [18]. In open-sea IMTA, the primary focus is on minimizing environmental impact, requiring the precise coordination of all components [19]. At a semi-industrial scale, land-based IMTA systems are being tested with various organisms to evaluate their interactions and suitability for commercial production [17,20]. Current research includes species such as sea bass, salmon, macroalgae, and crustaceans [17,20]. This research aims to facilitate the adoption of IMTA in the aquaculture industry and provides valuable insights into cultivating new species, such as the European brown shrimp C. crangon.

1.3. Socioecological Approach

From a socioecological perspective, the exploitation of C. crangon as a marine bioresource has a centuries-old tradition along the coasts of the North Sea and the Baltic Sea [21,22]. However, its capture method by beam trawling directly impacts the biodiversity, functionality, and overall health of these coastal ecosystems [21,22]. To ensure sustainable management, future studies should offer recommendations for exploiting C. crangon within an Ecosystem-based Approach (EA), with special emphasis on human dimensions including social, cultural, economic, political, and institutional factors [23]. Since the EA itself is a human-driven framework, these dimensions must be carefully considered when planning and implementing management strategies for this resource. The target audience for these recommendations should include fisheries and aquaculture managers, policymakers, researchers, coastal community leaders, industry stakeholders, and others involved in the development and execution of the EA. This approach requires an interdisciplinary integration of social, ecological, and biological network analyses to effectively manage this coastal resource [15,24].

1.4. Biological and Socioeconomic Attributes for Aquaculture Diversification

The European brown shrimp presents numerous biological and socioeconomic characteristics that make it a new/emerging species for the expansion of the European aquaculture industry [7,8,25]. For example, in Germany, this shrimp inhabits the North and Baltic Seas, where it is caught exclusively for direct human consumption. It has a long historical and socioeconomic–cultural tradition [4], which has helped maintain a stable market over time [5,26]. In relation to its biological features and potential, this shrimp has an extensive reproductive period during the year (from winter to summer) characterized by successive broods or clutches (i.e., eggs laid: 3–4 times per year) [27,28], with a high number of eggs produced in each reproductive event (ca. 2500 eggs) [27,28,29]. In addition, C. crangon larvae show a high nutritional tolerance [29,30], a wide thermal tolerance [31], and a high osmoregulatory capacity [32] during their successive instars [33,34]. These capacities allow them to survive and successfully complete their pelagic larval stage, resulting in the first benthic juvenile individuals in coastal environments [35]. The physiological flexibility of C. crangon, demonstrated by its high larval tolerance to environmental salinity changes [32] and its omnivorous habits with a wide trophic spectrum [31,36,37], makes it an ideal species for diversifying sustainable aquaculture and serves as a model for IMTA [1,7,38].

1.5. Life History and Nutrition

Recent studies on C. crangon have examined the temporal dynamics of adult energy reserves [39], as well as reproduction, larval phenology, and recruitment throughout the annual cycle in the southern North Sea [40,41]. However, it remains unclear how essential nutrients and bioactive molecules (e.g., lipids, fatty acids, proteins, amino acids, vitamins, and minerals) are obtained, stored, and utilized during early ontogeny. This is particularly important as an adaptive response to the pronounced seasonal variations in temperature, salinity, and food availability characteristic of the southern North Sea [42,43]. Although the significance of these nutrients has been extensively studied in other caridean shrimps [44,45,46], surprisingly little is known about their physiological roles in C. crangon, especially in supporting its survival in the dynamic and heavily exploited coastal environments of the southern North Sea [47,48].

Understanding the physiology of the lipids involved in reproduction and early crustacean ontogeny—particularly the biosynthetic capacity of essential long-chain polyunsaturated fatty acids (LC-PUFAs) such as ARA (20:4n-6), EPA (20:5n-3), and DHA (22:6n-3) [44,49]—is crucial for developing environmentally sustainable aquaculture systems. Species like the European brown shrimp, which are suitable for sustainable farming, can contribute to a blue bioeconomy by providing healthy food for consumers [1,50]. In this context, recent technological advances aimed at producing high-quality offspring [51] have shown that egg quality, hatching success, and larval survival across successive spawning events positively correlate with increased levels of ω3 LC-PUFAs (EPA and DHA) and ARA [52]. These levels are influenced by diet, water temperature, and habitat salinity [31,53]. Hence, future experiments should further analyze the influence of dietary lipids from different sources and varying water temperature and salinity on the egg production and larval development of the European brown shrimp. Moreover, the knowledge of nutrition, relevant reproductive biology (embryogenesis), and early ontogenetic development (larval phase)—all considered a “bottleneck” in crustacean aquaculture [49,54]—is critical for the successful production of captive shrimp, including our candidate species. Further understanding this species’ ecophysiology is also important to apply this knowledge to aquaculture production.

1.6. Husbandry Conditions and Production Cycle

The maintenance and rearing of C. crangon have been developed at a pilot experimental scale using recirculating aquaculture systems (RASs) [7,21]. These studies highlight the critical importance of husbandry techniques (e.g., stocking practices and water quality management) and rearing conditions (including temperature, feeding regime, salinity, and stocking density) in ensuring the successful cultivation of the species throughout its ontogenetic stages (i.e., larvae, juveniles, and adults) [7,8,33].

In larviculture specifically, pilot studies have shown that C. crangon undergoes six successive zoeal stages (ZI–ZVI), characterized by pelagic swimming behavior, followed by a benthic first juvenile stage (JI) [8]. Under optimal culture conditions (temperature: 15–18 °C; salinity: 32 PSU; feeding: Artemia nauplii), larval development from ZI to JI takes approximately 28 days [8,33]. Furthermore, it is estimated that the complete production cycle, from larval hatching through the juvenile stage to adulthood (approximately 80 mm in body length), can be completed within one year [7,37].

Taken together, the species’ favorable developmental traits (i.e., high fecundity, high larval survival rates, and rapid growth), along with behavioral characteristics such as low aggressiveness under controlled conditions, indicate that the full production cycle of C. crangon is feasible within the RAS frameworks [7,21].

2. Conclusions

The European brown shrimp (Crangon crangon) represents a species of considerable economic and cultural importance across North Sea-bordering countries. It is deeply intertwined with the maritime heritage and identity of these coastal communities, contributing significantly to traditional fisheries, local gastronomy, and cultural customs. Its value chain extends beyond local harvest areas to encompass markets throughout Europe, underscoring its broad socioeconomic relevance. Ecologically, C. crangon functions as a keystone species within the North Sea ecosystem, maintaining trophic balance by serving as a key prey species for various marine predators. Sustainable management practices, including catch quotas, seasonal closures, and size regulations, have been implemented in some regions to preserve wild populations and mitigate environmental impacts.

Nonetheless, the increasing demand for C. crangon, coupled with the effects of climate change and regulatory limitations, challenges the sustainability of wild fisheries alone. In this context, aquaculture presents a promising avenue to supplement supply and enhance the resilience of shrimp production systems. Although C. crangon aquaculture remains at an early developmental stage, this research perspective offers a novel contribution by advancing laboratory findings through the establishment of an Integrated Multi-Trophic Aquaculture (IMTA) system. This integrative approach aims to support sustainable production while safeguarding the cultural and ecological heritage associated with C. crangon, particularly in European countries such as Belgium, Denmark, Germany, and the Netherlands. Future interdisciplinary research should focus on optimizing aquaculture techniques, assessing ecological impacts, and integrating socioeconomic factors to ensure the long-term sustainability and acceptance of this emerging production method.