Using Citizen Science to Improve Our Understanding of Northern Shortfin Squid (Illex illecebrosus) and Longfin Inshore Squid (Doryteuthis pealeii) Ecology and Fisheries off Atlantic Canada

Abstract

Northern shortfin squid (Illex illecebrosus) and longfin inshore squid (Doryteuthis pealeii) are fished commercially and recreationally off Atlantic Canada, but limited reporting, particularly from recreational fisheries, has left major gaps in our understanding of their ecology and fishery dynamics. Our research used three years of data collected through citizen science initiatives, field visits, and commercial index harvesters to provide much-needed descriptions of squid fisheries and basic ecological characteristics, with a particular focus on Newfoundland and Labrador (NL). We documented active recreational squid fisheries landing both species, including the first confirmed observations of longfin inshore squid in the NL fishery. Distinct regional patterns emerged. North Coast Region fishers tended to use different gear and practices, achieved higher catch-per-unit effort (CPUE), and caught larger squid compared to other NL regions. South Coast Region fishers more frequently caught longfin inshore squid, and although relatively low CPUE was reported, this region tended to have a more active recreational fishery. Our findings reveal previously unrecognized regional variation in squid fisheries and highlight the need for improved understanding of squid ecology and the impacts of the recreational and commercial fisheries on the resource off Atlantic Canada.

1. Introduction

Northern shortfin squid (Illex illecebrosus) and longfin inshore squid (Doryteuthis pealeii) are thought to form single populations throughout the Northwest Atlantic [1]. Northern shortfin squid are distributed from Florida, United States, to southern Labrador, Canada [2], while longfin inshore squid are distributed slightly more southerly, from the Gulf of Venezuela to southern Newfoundland, Canada [3]. Both species are short-lived (<1 year) [4,5], partake in expansive migrations [5,6], exhibit strong environmental plasticity [7,8], and can display boom-and-bust population trends [9,10].

Squid have a strong cultural significance throughout Atlantic Canada, particularly in Newfoundland and Labrador (NL) [11,12,13]. Northern shortfin squid and longfin inshore squid are legally fished recreationally and, when abundant, can represent significant societal interest. The recreational squid fisheries in Atlantic Canada are unreported (i.e., there is no reporting mechanism or requirement to document effort or catch) and mostly unmanaged, with the exception of restrictions banning mobile gear and limiting use of catch (i.e., there are no licencing requirements and no effort controls). Northern shortfin squid are also the target of commercial jig, trawl, and trap fisheries off Atlantic Canada, where only total landings are reported by commercial harvesters, with the exception of eastern Nova Scotia that requires a monitoring document be completed. This lack of reporting has resulted in vast knowledge gaps related to the most basic details required to effectively manage any stock and its fisheries.

Both northern shortfin squid and longfin inshore squid are notoriously difficult to study, particularly off Canada, where their presence and catchability in bottom trawl surveys are strongly influenced by a number of factors, including specific timing and location of the surveys, time of day of the trawling event, environmental characteristics, and cohort strength. In the summer and fall, unknown proportions of the population off Canada can be found within inshore waters and therefore out of range of any current standardized marine survey. For example, since 1995, no longfin inshore squid have been recorded in the Fisheries and Oceans Canada (DFO) spring and fall multispecies trawl surveys off NL (DFO, unpublished data) and were thought to be rarely caught in the recreational fisheries. Northern shortfin squid and longfin inshore squid potential Canadian ranges span 11 degrees of latitude and more than 27,000 km of coastline, with large portions of the coast uninhabited between small communities, making any large-scale coastal surveys difficult. These features, in combination with the lack of adequate reporting in both commercial and recreational fisheries, have left significant deficiencies in our understanding of squid and their fisheries.

Throughout Atlantic Canada, we still have very little information regarding where squid are found, relative variation in abundance through space and time, distribution of fishing hotspots, location and timing of effort and catch, degree of effort, estimated catch, catch composition, and fishing gear used. Between 2019 and 2021, anecdotal reports suggested the highest availability of northern shortfin squid in decades throughout communities in Atlantic Canada, with squid beaching events and widespread recreational fishing activity [14,15]. This “boom” was also observed in commercial landings data (Figure 1—inset) but cannot be fully characterized because of the absence of data related to fishing effort. Nevertheless, this pulse renewed calls to broaden our understanding of the squid fisheries and ecology for effective, science-informed management.

We used three years of data collected through citizen science initiatives, field visits, and commercial index harvesters to describe basic characteristics of squid ecology and their fisheries throughout Atlantic Canada, with a particular focus on NL. We aimed to answer the following questions: When and where are recreational harvesters actively fishing for squid and how successful are they? What fishing gear and practices are most commonly used? Are there consistent regional patterns in catches, squid size, and species composition? We used our findings to highlight limitations, lessons learned, and directions for future work pertinent to the use of citizen science and field visits, with the aim of helping other researchers plan similar initiatives.

2. Materials and Methods

2.1. Dockside Scans

Dockside visits were performed for approximately 5–7 days each month between July and November in 2022–2024 throughout NL communities. Locations for dockside scans were chosen based on locality (e.g., driving distance from other areas or along planned driving routes), discussions with Harbour Authority representatives and local Fisheries and Oceans Canada (DFO) fishery officers, and scans of social media posts to identify prior or current evidence of recreational fishing activity. Visual scans were performed for a minimum of 5 min and the number of fishers observed, fishing gear types, and weather conditions were documented (Appendix A).

The scans were used to generally describe fishing patterns throughout the island of NL (e.g., number of fishers fishing from dockside versus from a vessel, size of vessels, gear being used, common fishing locations, and timing of fishing). A generalized additive model (GAM) with a binomial distribution was developed in R version 4.4.2 (Vienna, Austria) [16] with the package ‘mgcv’ [17] to describe factors influencing the probability of fisher presence. The presence (“1”) or absence (“0”) of fishers in every dockside scan was noted, and month, time of day (hour) of dockside scan, year, and region (Avalon Region, North Coast Region, or South Coast Region, Figure 1) were tested as predictors of fisher presence. Throughout this study, the best models were chosen based on the model’s ability to converge and Akaike information criterion (AIC) [18]. Model diagnostics were performed to assess residual patterns, evaluate the plausibility of smooth terms, and verify the overall adequacy of the fitted model.

2.2. Recreational Fishing Survey

A Squid Recreational Fishing Survey was created using ArcGIS Survey123 version 3.14 software (Redlands, CA, USA) [19]. Surveys were available online via the download of a smartphone application and use of a quick response (QR) code. To improve accessibility, surveys were also made available in a paper format that could be texted, emailed, or phoned in for those participants that were unable or did not wish to download an application to their personal device. The survey was designed to collect data on fishing locations, squid catch rates, effort, gear use, and weather conditions. Harvesters were prompted to enter data including start time, end time, number (and/or weight) of squid caught, gear use, and weather conditions, and they were encouraged to include photographs of the catch (Appendix B). Because longfin inshore squid were considered rare in recreational fisheries, there was no field to identify the species caught. However, this was noted in photographs, descriptions in the comments section, and by field staff whenever possible. Similarly, survey records were verified by photographs and field staff whenever possible.

Surveys were made available to the public using both passive and directed approaches. Surveys were distributed and completed in-person throughout NL from July to November (i.e., periods when fishers were likely to be recreationally fishing squid) by engagement with recreational fishers at community wharves and other potential fishing areas. Similarly to dockside scans, locations for directed efforts were chosen based on discussions with Harbour Authority representatives and local DFO fishery officers, social media posts, and locality (e.g., driving distance from other areas). Large outdoor posters and brochure cases containing paper surveys and business cards with the QR codes were installed across NL in an effort to increase awareness and engagement when routine in-person engagement was not feasible, such as in remote areas (Figures S1 and S2). Indoor posters, brochure cases, and business cards were distributed and hung in DFO field offices throughout Nova Scotia and New Brunswick, and small indoor posters were opportunistically displayed at outdoor sporting stores near Halifax, Nova Scotia. The survey was promoted online via DFO social media platforms and regional fishing social media groups, as well as through local media outlets. In addition, thank-you gifts ($100 gift cards to local outdoor sporting stores) were provided to random participants each year to help incentivize survey participation.

Summary statistics of the recreational surveys were used to describe general fishing practices, effort, and catch (e.g., gear being used, timing of fishing, successfulness of fishing, recorded catch, and seasonal effort and success). A GAM with a binomial distribution was developed to describe factors influencing the probability of recreational fisher success (i.e., at least 1 squid caught during a single recorded fishing trip). We considered the following potential predictors of fishing successfulness in model formulation: fishing day (number of days from 25 July; the first day of documented recreational fishing in our data), time of day (hour), fishing depth (m), gear (as factor), number of minutes spent fishing, year (as factor), and region (Avalon Region, North Coast Region, or South Coast Region). In addition, three metrics of catch per unit effort (CPUE) were calculated: CPUE_hr (number/hour), CPUE_hook (number/number of hooks), and CPUE_hook·hr (number/(hour ·hooks). The same potential predictors were tested within a GAM using a Tweedie distribution (link = log) predicting CPUE_hook·hr.

2.3. Commercial Index Harvesters

Commercial index harvesters were recruited throughout NL to record logbook-like data identifying their catch and effort from 2022 to 2024. Harvester locations were chosen to ensure broad spatial representation throughout NL. Data requested included information related to their vessel, gear, location of fishing, dates of fishing, and catch weight (Appendix C). Basic summary statistics were used to describe the commercial squid fishing practices and catch. Similarly to recreational fishing data, three metrics of CPUE were calculated: CPUE_hr (kg/hour), CPUE_hook (kg/number of hooks), and CPUE_hook·hr (kg/(hour·hooks)). Potential predictors of CPUE_hook·hr (i.e., fishing day—number days since 1 August because the first day of documented commercial fishing was 3 August in our data, year, fishing depth, fishing hour, use of lights, and a random effect of harvester) were tested within GAMs using a Tweedie distribution (link = log).

In addition to data collection, commercial index harvesters were asked to freeze 20 squid from their catch per fishing week of the fishing season, noting the location of the sample collection. These samples were thawed and each individual processed to identify species, total weight, total length, dorsal mantle length, sex, maturity, mantle weight, gonad weight, and digestive gland weight. Maturity was categorized based on gonadal development as 1 (immature), 2 (maturing stage I), 3 (maturing stage II), or 4 (mature) for males [20,21]. For females, one of five maturity stages were identified based on the ratio of nidamental gland length to dorsal mantle length [21,22]. Basic statistics of the morphometrics (e.g., mean and range) were calculated. A GAM was developed to evaluate potential trends in mantle length in relation to fishing day (i.e., number days since 1 August), year, bay of collection, and sex. Both Gaussian and Gamma (with a log link) distributions were tested in model formulation, and the best model was chosen based on AIC [18]. In addition, a multinomial model was fit for males and females separately using the R package ‘nnet’ [23] to evaluate how the probability of maturity stages changed with fishing day.

The reported catch from commercial index harvesters was compared with reported commercial squid catch in NL from 2022 to 2024 using DFO purchase slip data. All reported landings in purchase slip data were reported as northern shortfin squid, but the accuracy of this identification is unknown. These data were used to qualitatively evaluate the coverage and representativeness of the commercial index harvester data and results.

3. Results

3.1. Dockside Scans

From 2022 to 2024, 210 locations across the island of Newfoundland were visited by technicians for data collection and outreach (Figure S1). A total of 122 h of scans were performed over the three-year period to complete 709 dockside scans. The highest effort of dockside scans occurred in August (N = 197), September (N = 225), and October (N = 174), when squid are thought to be most abundant in NL inshore waters (Figure S3). The surveys occurred from 7:00 to 22:00, with the highest effort generally after 19:00 (Figure S4).

The dockside scans recorded 160 active squid fishers in 50 dockside scans (i.e., 7% of dockside scans reported active fishers), with the lowest number of fishers being reported in 2022 (N = 19) and the highest in 2023 (N = 86), with a particularly high number of observations in Placentia Bay (N = 38) of the South Coast Region. Across NL, 64.3% of fishers observed during dockside visits were fishing from dockside using jiggers on fishing rods or handlines (

Table 1. Summary of dockside scan efforts and findings based on different regions throughout the island of Newfoundland, 2022–2024.

	Avalon Region			North Coast Region			South Coast Region
	2022	2023	2024	2022	2023	2024	2022	2023	2024
Scans (#1)	25	78	65	97	140	174	37	58	35
Fishers jigging from dock (#)	1	25	22	0	2	5	3	44	1
Fishers jigging from boats (#)	7	5	1	8	6	26	0	4	0
Squid boats in water (#)	3	3	1	8	3	15	0	2	0
Squid boats tied to wharf (#)	3	13	3	3	47	116	0	0	1
Active fishing boats with hand-powered jiggers (#)	0	1	0	3	3	1	0	2	0
Total fishers (#)	8	30	23	8	8	31	3	48	1

¹# represents that number is the unit of measurement.

). However, in the North Coast Region, active fishers were more likely reported jigging from boats (75–100% of observed fishers annually). Boats used for fishing were primarily 20 ft (6.096 m) in length, and 28.6% were equipped with hand-powered squid jiggers.

Dockside scans were more likely to note the presence of fishers in the evening hours (~20:00) or morning (~7:00) (p = 0.034), and in the South Coast Region (p = 0.004) (Figure 2). Although month was not deemed a significant covariate in the model predicting fisher presence (p = 0.599), its inclusion in the model significantly improved the AIC values (model with month AIC = 344.88, model without month AIC = 353.83). Overall, the model explained a relatively low percentage of deviance (10.1%).

3.2. Recreational Fishing Survey

Large posters and brochure cases containing paper copies of Squid Recreational Fishing Surveys were placed on Harbour Authority buildings or nearby government wharves in 41 communities (Figure S1), and 210 locations were visited (comprising 709 visits) to promote the survey. In total, 132 surveys were completed between 2022 and 2024, with the highest number of surveys completed in 2023 (N = 80) and lowest in 2022 (N = 23).

The surveys were submitted from three regions of NL (North Coast Region, Avalon Region, and South Coast Region) in all years, but no surveys were submitted from the West Coast Region of NL or the Maritime provinces where only passive efforts to promote the survey were used in both areas. Low levels of independent survey participation were observed, with the majority (63.6%) of surveys completed and verified with technician assistance while dockside visits were conducted. The most surveys were submitted from the South Coast Region (N = 67) and submitted for fishing trips between August and October (Figure S5). The first reported fishing attempts in recreational surveys each year were on 25 July 2022, 27 July 2023, and 11 August 2024, and the last were 26 October 2022, 20 October 2023, and 23 October 2024.

In all years, recreational fishers preferentially used a handline or fishing rods to fish for squid, with only 17.4% reporting use of a hand-powered jiggers (

Table 2. Summary of Squid Recreational Fishing Survey results based on different regions throughout the island of Newfoundland, 2022–2024.

	Avalon Region			North Coast Region			South Coast Region
	2022	2023	2024	2022	2023	2024	2022	2023	2024
Surveys submitted (#)	12	10	14	6	9	14	5	61	1
Reported handlines/fishing rods (#)	8	10	14	5	4	5	5	56	1
Reported hand-powered jiggers (#)	3	0	0	1	5	9	0	5	0
Successful reports (#)	9	5	1	3	7	8	3	49	0
Mean duration (hours)	1.8	1.2	0.9	2.1	2.3	1.6	1.1	2.0	2.0
Reports targeting northern shortfin squid (#)	6	2	0	2	5	13	0	5	0
Reported targeting longfin inshore squid (#)	0	0	0	0	0	0	3	24	0

# represents that number is the unit of measurement.

). The North Coast Region tended to have a higher percentage of reported hand-powered jigger use (51.7%), compared to other regions (<10%). Only one recreational survey reported the use of a hydraulic jigger and no instances of hydraulic jiggers being used by recreational fishers were observed by technicians in the field. The number of hooks used by recreational fishers on the hand-powered jiggers was rarely reported (N = 11) but ranged from 50 to 250 hooks.

Survey participants reported fishing predominantly during evenings (between 18:00 and 22:00) (N = 129; Figure S6), in partly cloudy conditions (N = 49 of 77 entries) in ambient temperatures between 4 °C and 22 °C (average 13.8 °C; N = 94). Depth fished was on average 8.7 m, with reported fishing depth ranging from 1 to 100 m. Survey participants fished for less than an hour to 5.5 h at a time, with an average across all recreational surveys of 1.77 h per reported fishing trip.

A total of 64.4% of recreational surveys (N = 85) reported successful squid fishing efforts (i.e., at least one squid was landed). The probability of a successful fishing trip was significantly higher using a hand-powered jigger versus a handline or fishing rod (p = 0.003), in 2023 and 2022 compared to 2024 (p = 0.014), in ambient temperatures less than approximately 17 °C (p = 0.013), and throughout late-August to late-September (p = 0.004) (R²-adj = 0.518, deviance explained = 52.5%, Figure 3). There was no significant relationship with depth, but its inclusion in the model predicting a successful fishing trip significantly improved the model (AIC without depth in model = 100.84; AIC with depth in model = 78.04). All other potential predictors were not found to be significant and did not improve overall model performance.

Survey participants were provided the option to report their squid catch by counts of individual squid or by approximate weight (Appendix B). Most recreational fishers (96.2%) reported their catch in terms of a count, with a total of 2529 squid landed during reported fishing trips from 2022 to 2024. The highest number of landed squid reported in a single fishing trip was 240 northern shortfin squid, using a hand-powered jigger equipped with 200 hooks in White Bay (North Coast Region) on 17 September 2024. Only 10 recreational fishers reported their catch (when successful) using weight. A total of 634 kg of landed squid were reported by recreational fishers. The largest landed weight reported in a single fishing trip was 272.2 kg, using a hand-powered jigger equipped with 60 hooks in Bonavista Bay (North Coast Region) on 9 August 2023. A total of 62 surveys reported the species of squid targeted and/or landed. All reports that identified only longfin inshore squid (N = 27) or both longfin inshore squid and northern shortfin squid as the target species (N = 2) were from the South Coast Region (Table 2). All other reports identified only northern shortfin squid as the target species.

Recreational fishers were also given the opportunity to report on their effort and catch (in numbers or weights) throughout the fishing season up to and including the date of the survey submission (Appendix B). A total of 36 recreational fishers reported landing 10,571 squid and 2404 kg of squid over 1163 days of attempted fishing. Eleven of the twelve surveys that identified the seasonal species landed were from the South Coast Region and identified longfin inshore squid as the species mostly landed. The remaining survey that reported seasonal species breakdown (from the North Coast Region) identified northern shortfin squid as the only species caught. Recreational fishers that reported seasonal estimates often fished multiple times (e.g., 4–5 times) per week.

CPUE_hr (number of squid per hours fished) ranged from 0 to 150 squid/hour, with an average of 10.8 squid/hour. The maximum reported CPUE_hr was reported twice, both in Notre Dame Bay (North Coast Region) in 2024, albeit in different months, at different locations within the bay, and using different gears. CPUE_hook (number of squid per hook fished) ranged from 0 to 157 squid/hook, with an average of 12.7 squid/hook. The maximum reported was in Placentia Bay (South Coast Region) and although 24 were northern shortfin squid, the rest (133) were longfin inshore squid. CPUE_hook·hr (number of squid per hook hours fished) ranged from 0 to 150 squid/hook hours, with an average of 6.66 squid/hook hours. The maximum was recorded in Notre Dame Bay (North Coast Region) using a fishing rod/handline. CPUE_hook·hr was greatest using handlines or fishing rods (p = 0.015), in the North Coast Region (p = 0.032), in ambient temperatures less than approximately 7 °C (p < 0.001), from late-August to late-September (p < 0.001), and peaked at depths near 30 m (Figure 4, R²-adj = 0.756, deviance explained = 64.5%). Year was not a significant predictor of CPUE_hook·hr but improved the overall model performance (AIC with year included: 349.97; AIC without year included: 377.80). All other potential predictors of CPUE_hook·hr tested in model formulation were not found to be significant and did not improve the model performance.

Recreational fishers were asked to report on the abundance of squid in the current fishing year compared to the previous fishing year, if possible. In 2022 (N = 22), 90.9% of fishers reported squid abundance to be much less than observed in 2021 (Figure S7). In 2023 (N = 64), 92% of fishers reported abundance to be much more (N = 28), slightly more (N = 18), or about the same (N = 13) as 2022. In 2024 (N = 20), 85% described the abundance of squid to be much less (N = 7), slightly less (N = 6), or about the same (N = 4) as 2023. These patterns were generally consistent throughout all three regions, but the potential increase noted from 2022 to 2023 was more pronounced in the South Coast, where all but one of the entries for “much more” in 2023 were recorded.

3.3. Commercial Index Harvesters

A total of 25 commercial index harvesters were recruited over the course of the project. Despite this, not a single commercial index harvester reported any squid fishing activity in 2022; one reported fishing and provided data for 12 sets in 2023, and four harvesters reported data for 33 sets in 2024 (i.e., total N = 45). All commercial index harvesters that reported fishing consistently fished in Notre Dame Bay, with the exception of one in Conception Bay, and used 6.10–9.14 m (20–39 ft) vessels. They began fishing in early to mid-August, usually within days of each observing their first squid inshore, but there was wide variability in end dates (mid-September to mid-November). Per fishing trip, harvesters spent 1 to 18 h (average = 5.3 h) searching for commercially viable squid fishing locations and spent 1 to 5.5 h fishing in water depths ranging from 14 to 38 m. The harvester in Conception Bay travelled farther from port, spent more time searching, and fished in less consistent locations than those in Notre Dame Bay. Harvesters reported 0 to 15 fishing sets per year. One harvester used a hydraulic jigger with 1300 hooks consistently, while all others used hand-powered jiggers, with the number of hooks varying from 30 to 240. Harvesters that did not report a consistent number of hooks gradually added more hooks during the fishing season. For one set, a harvester also tried fishing with a net rather than a hand-powered jigger. Harvesters reported setting their fishing gear in the early evening and early morning hours (Figure S8). One index harvester did not report the time of day that their fishing gear was set but was the only harvester that reported using lights for fishing, and the use of lights was reported for all of that harvester’s reported fishing sets.

Due to the limited data, precise information regarding fishing catch was not reported at a bay level and instead was summarized at the provincial level. Commercial index harvesters reported 14.80796 t of catch (2023: 11.50581 t, 2024: 3.30215 t) during the study. CPUE_hr ranged from 0 to 5674 kg/hour (mean: 206 kg/hour), CPUE_hook ranged from 0 to 63.04 kg/hook (mean: 1.85 kg/hook), and CPUE_hook·hr ranged from 0 to 31.52 kg/hook*hour (mean: 1.12 kg/hook·hour). The scarce data resulted in limited model fitting possibilities; however, the best model included year (p = 0.007), fishing day (p < 0.001), fishing hour (p = 0.019), and a random effect of harvester (p = 0.081) as predictors of the reported CPUE_hook·hr (Figure S9, deviance explained = 65.3%, R²-adj = 0.369).

A total of 326 northern shortfin squid from 14 sets were collected from the commercial index harvesters to describe catch composition. No longfin inshore squid were collected. The samples were from fishing trips spanning 3 August–6 September in 2023 and 22 August–5 November in 2024. A total of 150 females, 173 males, and 3 unknown sexes were reported and ranged in size from 147 mm to 290 mm in dorsal mantle length and 49.5 to 607.7 g in total weight (

Table 3. Summary statistics of northern shortfin squid (Illex illecebrosus) samples collected from commercial index harvesters in 2023 and 2024 off the island of Newfoundland.

	Mean (Range)
	Males	Females
Dorsal mantle length (mm)	213 (164–276)	213 (147–290)
Total weight (g)	218 (71.5–607.7)	206 (49.5–532.1)
Gonad weight (g)	2.2048 (0.0365–10.9477)	0.3287 (0.0126–2.2699)
Digestive gland weight (g)	25.53 (4.30–82.30)	26.65 (3.20–75.20)

). There was a significant positive relationship between fishing day and mantle length (p < 0.001): 2023 squid were slightly larger than 2024 (p <0.001), squid collected in Notre Dame Bay were slightly larger than Conception Bay (p < 0.001), and females were slightly larger than males (p < 0.001), but the low sample size likely caused unknown sexes not be significantly different than sexed individuals (p = 0.3572) (Figure 5, deviance explained = 99.4%, R²-adj = 0.61). Maturities ranged from 1 to 4 for males and 1 to 3 for females (i.e., no mature females were observed). Date of fishing had a significant, positive effect (p < 0.001) on the probability of each northern shortfin squid maturity stage being caught in the fishery (Figure 6).

In 2022, there were more than zero but less than five buyers and active commercial harvesters of squid off NL, so the precise landings could not be reported [24]. However, landings were among the lowest in the timeseries. In 2023 and 2024, 116.9 and 19.9 tonnes of commercial catch were reported off NL by 66 and 11 harvesters, respectively (Figure 1—inset). Therefore, although few commercial index harvesters fished during the study years, the index harvesters who did report fishing represented 10–16.6% of the total commercial squid catch reported and 1.5–36.4% of the active harvesters, with 2024 commercial index harvester data being much more representative of the total commercial fishery off NL. Similarly to the catch from commercial index harvesters, in 2023, the majority of the reported catch was from the North Coast Region. However, in 2024, a single harvester reported the most catch from the West Coast Region.

4. Discussion

Our research used citizen science initiatives to better understand the ecology and fisheries of squid off Atlantic Canada, particularly NL (

Table 4. A summary of key findings related to gear, region, and year from models interpreting squid fisheries using dockside scans, recreational surveys, and commercial index harvester logbooks and samples collected off Newfoundland and Labrador (2022–2024).

Metric of Interest	Key Findings
Probability of a squid fisher present during a dockside scan	South Coast Region > Avalon Region/North Coast Region
Probability of a successful recreational fishing trip	Hand-powered jigger > fishing rod 2023 > 2022 > 2024
Predicted CPUE (number of squid per hook hours fished) in the recreational fishery	Fishing rod > hand-powered jigger North Coast Region > Avalon Region/South Coast Region
Predicted CPUE (number of squid per hook hours fished) in the commercial fishery	2023 > 2024
Mantle length of squid caught in the commercial fishery	2023 > 2024 Notre Dame Bay > Conception Bay

). We documented consistent recreational squid fisheries targeting northern shortfin squid and, somewhat surprisingly, longfin inshore squid, even in years of relatively poor squid availability throughout inshore areas. In the years of the study, fishers from the North Coast Region, NL, tended to use different fishing practices (e.g., hand-powered jiggers rather than handlines or fishing rods), exhibit higher CPUE_hook·hr, and documented squid relatively larger in size compared to other NL regions. South Coast Region fishers tended to catch and target longfin inshore squid, and although relatively low CPUE_hook·hr was reported, this region tended to have a more active recreational fishery.

4.1. Squid Ecology

The South Coast Region of NL represents the northern-most edge of longfin inshore squid’s documented range, but longfin inshore squid have never been identified during annual spring trawl surveys of the area (DFO, unpublished data) and the species has never been documented off NL on iNaturalist [25]. Despite this, our Squid Recreational Fishing Survey found an active and successful recreational fishery for this species in the South Coast Region. In 2023, technicians conducting dockside scans in Conception Bay (Avalon Region) also heard from recreational fishers that squid caught in evenings prior to the dockside visit were “different” and “more soft and delicate”. Although unconfirmed, these anecdotes likely indicate the presence of longfin inshore squid farther north in 2023 as well. Dawe et al. [26] also reported catching longfin inshore squid in Conception Bay in one year (1986), despite multiple years of trapping effort there. Although no Squid Recreational Fishing Surveys were submitted from Nova Scotia, a posteriori social media scans of Facebook groups that report fishing and sightings of squid, capelin (Mallotus villosus), whales, mackerel (Scomber scombrus), and other species in Nova Scotia and NL confirmed the presence of longfin inshore squid (via photographs) throughout Nova Scotia’s Atlantic Coast in all years of the study, with particularly plentiful records in recreational fishing during 2023. Their presence during the study was further confirmed off Nova Scotia, New Brunswick, and Prince Edward Island in iNaturalist-verified reports [25]. The last available assessment of longfin inshore squid included data up to 2022 and showed an increasing trend of biomass in recent years [10]. In 2023, recreational fishers in the South Coast Region, NL (where they primarily caught longfin inshore squid) identified more abundant levels compared to previous years, indicating 2023 to be a particularly plentiful year in this region.

The potential adverse effects of climate change (specifically ocean acidification) on longfin inshore squid development have been well-documented (e.g., [27]), but warming waters at the northern extent of its range [28] could result in more common occurrences through this area, as well as possible range expansions into other areas of NL, where they were previously considered rare [26]. Climate-driven poleward range expansions have been noted in multiple squid species (e.g., [29,30]). Doryteuthis opalescens, a similar Pacific species, was observed 1200 km north of its typical range in recent years [31]. With the help of community-based research, this range expansion was attributed to competitive release and climate-related temperature increases and oxygen loss [31]. Range expansions and an overall increase in biomass related to climatic changes were also found in multiple squid taxa over a 35-year time period in the North Sea [32].

Longfin inshore squid migrate to coastal spawning grounds from the edge of the continental shelf off northeastern USA in the springtime (large individuals) and summer (smaller individuals) [3,33]. Off Canada, spawning grounds have been noted in the Bay of Fundy (August to September), the eastern coast of Nova Scotia (spring to late-summer), and the Scotian Shelf and Georges Bank (spring to late-summer) [3,26]. Although longfin inshore squid spawn year round [34], these previously reported seasonal and geographic peaks, in combination with their timing within inshore waters off NL at the extent of their range in our surveys (August to October), highlight the need to evaluate catch composition of the recreational and commercial fisheries and further search for and document potential spawning grounds in this area.

No Squid Recreational Fishing Surveys were submitted from West Coast Region of NL or the maritime provinces, but northern shortfin squid were confirmed to be present in West Coast Region via records of commercial landings in the area (DFO, unpublished data) and off Nova Scotia through social media posts. iNaturalist-verified records of northern shortfin squid generally concurred with our reported sightings off Newfoundland, but documented the species as far north as Labrador in 2023 and 2024 [25]. In general, northern shortfin squid abundance within inshore NL waters is thought to follow boom-and-bust trends. Since launching the survey in 2022, reported NL landings of northern shortfin squid drastically declined compared to the previous “boom” years between 2019 and 2021 (Figure 1—inset). The responses in the Squid Recreational Fishing Surveys also describe a large decline in availability between 2021 and 2022 that, with the exception of South Coast Region (that was likely highly represented by longfin inshore squid), did not bounce back to previous levels. Dawe et al. [26] hypothesized that longfin inshore squid may be prevalent in NL during years when northern shortfin squid are not. Our research further supports that hypothesis.

Our findings support other work that suggest northern shortfin squid likely form one population throughout their range, with individuals found off NL resulting from cohorts spawned off the USA. These squid follow the Gulf Stream north in spring, then move from the offshore to inshore waters in the pursuit of prey during summer and early autumn. In late autumn, the squid are thought to move back offshore, then return south to their spawning grounds [35]. Off NL, successful fishing efforts generally began in late July and extended into the fall months, although the probability of success began to wane by mid-September. The commercially caught squid showed a clear and consistent increasing trend in mantle length with time since 1 August, as well as larger squid in the more northern regions, potentially indicating the lack of continuous new cohorts in the area. In addition, although we found clear patterns that northern shortfin squid were maturing in NL waters throughout the summer and fall, we found no mature females in the commercial samples of catch. This is consistent with previous reports that female northern shortfin squid usually begin to mature as they move south to their spawning grounds and that males mature faster in Newfoundland waters [35,36].

4.2. Squid Fishing Practices

Although the seasonal and daily timing of squid fishing was relatively consistent between years and regions, our results suggest variability of squid fishing practices throughout NL. Most notably, hand-powered jiggers were more commonly used by recreational squid fishers in North Coast Region compared to other regions. In some cases, these hand-powered jiggers were equipped with more than 200 hooks, indicating substantial investment for a recreational fishery.

Over 50% of the population of NL live in the Avalon Region, so high efforts in this area were expected. In addition, following the number of postings of squid fishing on social media, we expected to see the most reliable presence of recreational fishers (and also highest catches) in the Avalon Region, particularly Conception Bay. However, the probability of fishers being present appeared to be highest in the South Coast Region. Although it was known that recreational fishing was occurring in the South Coast Region, the overall reliability of active fishers in specific areas of the region was somewhat surprising, particularly since northern shortfin squid was not considered abundant in the years of the study. This region did not tend to have highly active social media postings highlighting squid sightings and catch results and without any reporting of recreational catch, the efforts were unknown. Discussions with fishers in this region highlighted their general preference to keep specific locations and timing of squid catches to themselves. The stronger presence of recreational fishers in this region compared to other regions could simply be the result of targeting another species (i.e., longfin inshore squid) that appeared to be particularly abundant during the timeframe of the study.

Inshore commercial squid fisheries off Atlantic Canada are considered opportunistic fisheries [12]; commercial harvesters participate in the fishery if squid are readily available, the timing is appropriate compared to other fishing ventures, and there is a market. The commercial index harvesters reported catch and effort somewhat later in the season than recreational harvesters. This could be caused by a number of factors, including the desire to target larger squid, increased squid availability in the specific area fished, or the seasonal closure of more lucrative fisheries (e.g., snow crab—Chionoecetes opilio) that many harvesters also participate in.

Our study suffered from what was considered low squid availability through most of NL, resulting in what we assume is the extreme low end of recreational squid fishing efforts, compared to efforts anecdotally reported from 2019 to 2021, and often confirmed by recreational fishers during dockside visits. It is unknown if the patterns of recreational and commercial squid fishing practices would hold true in years of high northern shortfin squid availability and how these patterns will shift with changing climatic conditions. We recommend conducting comparable research during years of high northern shortfin squid abundance to provide insight into potential variations in our findings.

4.3. Squid Fishing Catch

The probability of a successful fishing trip was highest when hand-powered jiggers were used, rather than a handline or fishing rod. This is likely the result of recreational fishers making the effort to equip and fish with hand-powered jiggers only when squid were confirmed in the area. On the other hand, recreational fishers would often pass the time attempting to fish with fishing rods in previously successful squid fishing locations, even if there were no recent catches in the area.

The highest predicted estimates of CPUE_hook·hr from the Squid Recreational Fishing Survey were reported in the North Coast Region, where most commercial index harvesters also reported catches. Catch rates and reported commercial landings were particularly low in both commercial and recreational fishing efforts in 2024, representing a low year of squid availability off NL.

Although 2022–2024 represented a timeframe of low northern shortfin squid catches (i.e., “bust” years) off NL, squid landings (or lack thereof) can have substantial impacts on the provincial economy. In 2021, the NL commercial squid fishery landed value was more than 16 million CAD [37]. In the years following high squid abundance, many NL snow crab harvesters (a 1.4 billion CAD industry, [38]) greatly reduce their cost of bait by simply supplementing their bait source by fishing for squid in the previous year. In contrast, when there is low squid availability, snow crab harvesters heavily rely on imported bait (e.g., Argentine shortfin squid—Illex argentinus) (DFO, unpublished data).

4.4. Lessons Learned and Future Considerations

Citizen science has long been shown to be an effective data collection tool in ecology through examples such as the North American Breeding Bird Survey [39] and the North American Waterfowl banding program [40]. In fisheries science, citizen science can be used to fulfil important research initiatives and complement structured surveys and monitoring by extending coverage and filling data gaps [41,42,43]. Cephalopod-specific examples include the documentation of ommastrephid egg masses off Norway and the Mediterranean using citizen science records between 2001 and 2017 [44], and descriptions of cuttlefish hunting behavior from videos collected from citizen scientists [45]. However, the direct use of citizen science data in fisheries assessment and management is somewhat limited albeit growing in popularity [41,42]. For example, the Marine Recreational Information Program, operated by National Oceanic and Atmospheric Administration (NOAA) Fisheries, is a strong example of citizen science use in fisheries. The program represents the primary data collection method used to assess recreational catch and effort of angled fish for use in stock assessments. Our results provide the foundational support to improve future squid assessment and management by strongly highlighting the very need for the incorporation of recreational fishing data and Canadian longfin inshore squid patterns data into the ongoing assessments and management considerations.

Our study is limited by a short three-year timeframe, a small number of commercial participants, low independent recreational survey participation, and uneven regional coverage, affecting the representativeness of our findings. No Squid Recreational Fishing Surveys were submitted from the West Coast Region, NL or the Maritime provinces, where passive efforts to promote the survey were used. Throughout other parts of the island of Newfoundland, the majority of surveys were completed with technician assistance while dockside visits were conducted. These results highlight the difficulties of citizen science and the requirement for strong in-person engagement. The low independent participation may result from numerous causes including (but not limited to), lack of trust in government departments (i.e., feeling of being used or fear of contributing to the potential implementation of stricter regulatory measures), desire to keep fishing catch and efforts undisclosed, one-way communication of online data collection, lack of time to commit to completing surveys, and/or a general lack of interest in research [46]. Future citizen science efforts used to understand squid fishing in Atlantic Canada should continue to use in-person, directed methods and feedback loops to ensure fishers have the opportunity to see how their data are (and, sometimes most importantly, are not) being used to foster trust and build relationships with community members [47].

Many respondents that reported independent records used the text-in or email-in options, preferring not to download a mobile application to submit their data. Within the ageing population in many remote communities throughout Atlantic Canada, such options would likely be considered a requirement for participation. An additional alternative approach may be using a QR code that redirects to a website for survey completion. Other options for citizen science squid data collection could include actively collecting data through a social media group established to record such information. From our perspective, we noted that in certain areas of NL and Nova Scotia, fishers regularly shared their catch and effort information with the public. Nevertheless, our results also indicated a lack of social media participation in specific areas, and many fishers throughout NL stated their desire to keep their precise fishing records private in hopes to reduce an influx of fishers to specific areas. Therefore, even if social media was used as an avenue for data collection in the future, efforts for in-person data collection would likely need to continue to be pursued for a more fulsome understanding of squid catch and effort.

Illegal selling of recreational squid catch is an ongoing concern throughout NL, particularly in years of high squid abundance. Frustration with this, and lack of reporting and monitoring in the recreational fishery, was routinely voiced by commercial harvesters. Recreational fishers practicing such activities would most likely represent excessively high catch metrics, and regardless of the efforts used for citizen science data collection, would continue to go unreported to avoid their detection and presence.

5. Conclusions

Northern shortfin squid and longfin inshore squid distribution, abundance, and ecology will continue to change as climatic conditions throughout their ranges are altered [48]. The northern limit of their ranges may extend north and areas of high squid abundance off Atlantic Canada may become more common. Understanding and tracking such changes in the dynamics of each species and their resulting fisheries will be essential for proper resource management. Northern shortfin squid is assessed as two stock components (Northern and Southern Components). The Northern Component includes the Canadian range of the species and is assessed by the Northwest Atlantic Fisheries Organization (NAFO); however, the assessment does not include any information related to catch and effort of the very active recreational fishery throughout Atlantic Canada [9]. Currently, off the USA, longfin inshore squid is managed by the Mid-Atlantic Fisheries Management Council and assessed nationally. Despite a clearly active recreational fishery throughout Nova Scotia and the South Coast Region of NL (that occurs without required permits or reporting) and indications that longfin inshore squid may represent a single stock unit [3], there is no such assessment off Canada and no integration of this fishery in the USA assessment. The widespread and active nature of these recreational fisheries throughout Atlantic Canada, in combination with the assumed single-population structure [48], the importance of squid to the ecosystem as both predators and prey [49,50], and changing environmental conditions [48], all highlight the need to more fully understand squid ecology off Atlantic Canada and quantify the impact (or lack thereof) of recreational and commercial fisheries on the resource.