Sea turtles encounter numerous anthropogenic threats to their survival, including vessel strikes, entrainment in dredging equipment, debris ingestion, and incidental capture and entanglement in both commercial and recreational fishing gear (Dickerson et al. 2004; Moore et al. 2009; Lewison et al. 2014; Wilson et al. 2014). While interactions between commercial fisheries and sea turtles have been well studied and regulated, the scope of bycatch in the recreational hook and line fishery in the United States remains largely undocumented and thus unaddressed. US and binational recovery plans for both loggerhead sea turtles (Caretta caretta) and Kemp's ridley sea turtles (Lepidochelys kempii) indicate that minimal data exist describing hook and line interactions for either species, and the Kemp's ridley plan specifically identifies the reduction of hook and line interactions as a high priority action (National Marine Fisheries Service and US Fish and Wildlife Service [NMFS and USFWS] 2008; NMFS et al. 2011).

Published studies of hook and line fishery interactions with sea turtles primarily involve the commercial longline fishery. Estimates of postrelease mortality due to longline hook ingestion in loggerhead sea turtles suggest that mortality occurs in 25%–30% of cases, with deep-hooking interactions resulting in mortality of up to 55% (Casale et al. 2008; Swimmer et al. 2014). Studies that observed turtles postinteraction in a captive setting found that capture by longlines and branch lines may prove fatal in a short amount of time due to forced submergence (in anchored gear) and from sharp trauma from the hook resulting in perforations of the heart, blood vessels, or gastrointestinal (GI) tract (Casale et al. 2008). This study also identified chronic and fatal impacts of line ingestion, with death occurring after a relatively long period of time (up to 45 d), due to the ingested line causing starvation and/or intestinal intussusception and subsequent tearing. Additionally, deep hook ingestion (in the stomach and lower intestine) presents a greater risk of mortality than hooks in the esophagus and mouth, although these hooks still pose a threat to survival.

Commercial longlines present a threat to sea turtles and numerous bycatch mitigation studies have shown effective measures for reducing bycatch in this fishery (Gilman and Huang 2017). Modifying hook shape, such as substituting circle hooks for J-hooks, effectively reduces sea turtle longline bycatch by as much as 65% per species, with circle hooks also reducing the likelihood of a deep hooking event (Sales et al. 2010). This study also found that modifying bait type by switching to cut fish from squid bait also resulted in less sea turtle bycatch while maintaining target species yield. These studies demonstrate some of the simplest and most tangible examples of mitigation measures, although fisheries-specific measures such as time-area closures to avoid sea turtle bycatch hotspots can further reduce interactions between sea turtles and commercial gear.

Current literature contains insufficient data to characterize overlap in recreational fishing effort and active sea turtle habitat, the scope of bycatch, or angler fishing habits and circumstances that influence interaction frequency. Studies of morbidity and mortality risks and rates of interaction of freshwater turtle taxa with recreational fisheries may provide a comparison and a potential proxy for sea turtles. In a study of ingested hooks found in freshwater turtles, hooks were found in up to 36% of turtles depending on age class (Steen et al. 2014). In this study, the greatest proportion of hooks were found in common snapping turtles (Chelydra serpentina) located in heavily trafficked waterways, with a greater frequency found in adult females (33%) than adult males (10%), likely due to the larger body size of females and their ability to ingest relatively large hooks. Enge et al. (2014) found hooks in 12% and 36% of alligator snapping turtles (Chelydra spp.) in 2 Florida rivers. Due to their large size relative to other freshwater taxa, studies of common snapping turtles and alligator snapping turtles may be especially useful in comparisons with the marine taxa that are encountered by recreational anglers, especially juvenile Kemp's ridleys.

Several previous studies report sea turtle bycatch in recreational fisheries, predominantly Kemp's ridley sea turtles, largely from fishing piers in states bordering the Gulf of Mexico (GOM), including Florida (Rudloe and Rudloe 2005), Texas (Cannon et al. 1994; Seney 2008), and Mississippi, Louisiana, and Alabama (Coleman et al. 2016). Reports of hooked sea turtles increased drastically in the Mississippi Sound following enhanced sea turtle response and rescue in the wake of the Deepwater Horizon oil spill disaster response. After experiencing a higher number of hooked turtle reports in 2013 and subsequently initiating a targeted outreach program at fishing piers, Virginia's reports of sea turtles hooked by recreational anglers rose consistently from 2014 to 2018. Notably, in the absence of federal or state oversight in the interactions between sea turtles and recreational fisheries, conservation managers continue to address interactions and collect data to varying specificity.

This study reports data for threatened loggerhead and green (Chelonia mydas) sea turtles and critically endangered Kemp's ridley sea turtles incidentally caught in the Virginia recreational hook and line fishery from 2014 through 2018. These data include demographics, health parameters, and the nature of interactions to better understand the potential impact of recreational bycatch on seasonally occurring sea turtle species in the temperate foraging habitat of Virginia.

METHODS

In 2014, the Virginia Aquarium Stranding Response Program (VAQS) initiated the Virginia Aquarium Pier Partner Program (VAPPP), a targeted fishing pier outreach campaign that conveyed the importance of reporting bycaught, or “hooked,” sea turtles to stranding response organizations. This outreach program, modeled after the Loggerhead Marinelife Center's Responsible Pier Initiative (RPI; Loggerhead Marinelife Center 2020), provided recreational anglers with the knowledge and tools needed to safely land and report hooked turtles to experienced sea turtle professionals. The VAPPP included the installation of instructional pier signage regarding safe landing procedures with VAQS hotline information, as well as lift nets and rescue boxes to contain turtles at pier locations while awaiting pickup by responders. The VAPPP included 7 “pier partners,” whose management supported the VAPPP's mission to document and safely retrieve hooked turtles. This included 2 piers along the Atlantic Coast and 5 piers on the southwestern shore of lower Chesapeake Bay, as the majority of reported recreational bycatch of sea turtles occur at piers in the Hampton Roads region of southeastern Virginia (Fig. 1). In addition to the installation of pier signage, targeted outreach to anglers was conducted by VAQS via regular pier visits throughout the primary pier fishing season (April–November) from 2014 through 2018.

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In addition to the education and outreach, VAQS surveyed recreational anglers at the partner piers to collect baseline information on the fishery from piers (referred to as “angler surveys”). These surveys were a modified version of a recreational angler survey developed by the National Oceanic and Atmospheric Administration (NOAA) Fisheries Pascagoula laboratory regarding fishing habits such as frequency of fishing, bait and gear type(s) used, and awareness of educational signage (Cook et al. 2020). From 2014 through 2018, VAQS conducted surveys, primarily from May to October with additional surveys added in April and November in the 2017 season. Volunteers were given monthly target quotas for number of surveys per pier (depending on the current number of surveys conducted), surveyed anglers from the entire pier length, and varied the time of day during which they conducted surveys to best approach even survey coverage. The total number of surveys was reduced in 2018 and eliminated in 2019.

To maintain consistency between angler-reported hook type in angler surveys and hook types found by staff during turtle examination, angler surveyors used a hook identification card to confirm hook type. For bait type, “artificial bait” was defined as flavored material placed on a hook and was placed in a different category from lures. If bait of any type was added to a lure, it was categorized as the added bait. If a naked lure was used (without bait) it was categorized as a lure. In some cases, if anglers reported using more than one type of bait, surveyors recorded “primary bait” as the bait type anglers indicated they used more frequently. For bait analyses, only primary bait type was used. A variety of species were included in the “cut fish” bait category, but whole dead and whole live fish were placed into separate bait categories.

Hooked Sea Turtle Data Collection and Comparison. — All recovered hooked turtles were admitted to the VAQS Marine Animal Care Center and received a physical exam, blood sample collection, radiography, and hook removal whenever possible. Upon initial exam, turtles were classified as critical, fair, stable, or presumed healthy based on calculated body condition index (BCI), hooking severity, presence of previous hooks, and presence of injuries or other clinically significant conditions secondary to the hook interaction(s). BCI was calculated using Fulton's K index (K = [M/L³] × 10,000, where M = mass in kilograms and L = straight carapace length [SCL], notch-to-tip in centimeters) for all turtles with accurate SCL and M measurements (Fulton 1902; Bjorndal et al. 2000; Nash et al. 2006). Secondary conditions included vessel strike trauma, entanglement, ocular lesions, anemia, and any other medical conditions that would extend hospitalization for treatment. Hook interactions were categorized as “fair” when the turtle was hooked in the mouth or esophagus and “foul” when the turtle was hooked externally in other areas, typically a front flipper.

Within 48 hrs of response, blood was drawn from the dorsal cervical sinus of each turtle using a 21-gauge, 1–1.5-inch needle and 1.0–3.0-ml syringe. Blood from each turtle was divided between 1 to 2 lithium heparin plasma separator tube(s) and/or a lithium heparin whole blood tube. Bloodwork was processed in house and/or sent to an outside laboratory (IDEXX and/or University of Miami, Avian & Wildlife Laboratory) based on the health classification of the animal.

Targeted data collection regarding the hooking event was attempted for all reported hooked turtles by interviewing the angler who caught the animal (referred to as “angler interviews”; see Supplemental Material S1 and S2, available at http://dx.doi.org/10.2744/CCB-1476.1.s1 and s2, for interview questions), usually during the initial reporting phone call, with in-person follow-up when possible. These data included (among others) bait and gear type used, hook location, how turtle was landed, and how the angler knew to report the interaction. Additional hook data were collected for turtles admitted to rehabilitation and included radiographs, photo documentation, and measurements of hooks, as well as hook type classification for intact hooks (removed without cutting or otherwise deformed).

Partial interviews were conducted with other anglers or pier management who directly observed the interaction or obtained information from the angler or witnesses to the interaction when the primary angler was not available or not interested in being interviewed. As the project progressed, interview questions were added or modified, resulting in less or slightly different data during the earlier years of the project. It should be noted that while pier anglers were the target of outreach efforts, VAQS also received a small number of additional reports of hooked turtles from recreational anglers fishing from boats, beaches, and other local nonpier venues, also included in our analyses.

Records of live and dead, otherwise “stranded,” sea turtles were used as a comparison group for the hooked turtles in this study. Since VAQS coordinates stranding data collection and operates the only sea turtle rehabilitation facility in Virginia, data were available for all sea turtle records in the state. These data included basic stranding and morphometric data for deceased animals and clinical assessment data from live animals admitted into rehabilitation for causes other than recreational hook and line interactions and provided a robust baseline data set from which to compare the emergent group of hooked turtles. Data records were also available for wild-caught turtles obtained using a variety of methods and captured under National Marine Fisheries Service (NMFS) Endangered Species research permit 16134, which was active from August 2012 to October 2017.

Data Analysis. — Data were analyzed using R 4.0.0 (R Core Team 2020). When data were normally distributed (Shapiro-Wilk test for normality) with equal variance (Levene's test), either an independent samples 2-way t-test or 1- or 2-way analysis of variance with Tukey post hoc pairwise comparison was used, depending on the number of variables. If data were proportions, not normally distributed, or had strongly unequal variances, nonparametric tests were used, including a 2-sample Wilcoxon rank sum test, Kruskal-Wallis test with Tukey and Kramer post hoc comparison in the R package PMCMR (Pohlert 2014), and χ² and contingency tables with post hoc analyses using Bonferroni corrections following MacDonald and Gardener (2000).

RESULTS

Demographics of Bycaught Sea Turtles. — VAQS received 250 reports of turtles incidentally captured by recreational anglers from 2014 to 2018. There were 25, 47, 55, 57, and 66 interactions reported, respectively, from 2014 to 2018. These reports included 162 Kemp's ridleys, 45 loggerheads, 4 greens, and 39 unidentified sea turtles. Reported interactions occurred between the months of April and November, including 6 (2%), 91 (36%), 72 (29%), 30 (12%), 20 (8%), 14 (6%), 14 (6%), and 3 (1%) from April to November, respectively. Of the 250 reported interactions, 170 (68%) were recovered for exam, including 147 (87%) Kemp's ridley sea turtles, 19 (11%) loggerheads, and 4 (2%) green turtles. The 80 turtles not recovered for exam included 26 (33%) loggerheads, 15 (19%) Kemp's ridleys, and 39 (49%) unidentified sea turtles. Turtles were not recovered when the animal broke the line or self-released, or the angler cut the line. All but 2 turtles (99%) were examined, treated as necessary, and subsequently released. Two Kemp's ridleys died as a result of hook interactions: 1 turtle was euthanized due to the extent of hook trauma and a second died as a result of fatal esophageal hook perforation.

Significant differences between the dates of capture (in Julian days) were noted between Kemp's ridleys and loggerheads. Although the first (day 117 for Kemp's ridleys; day 118 for loggerheads) and last (day 310 for Kemp's ridleys, day 294 for loggerheads) Julian days Kemp's ridleys and loggerheads were hooked were similar, the mean Julian day of Kemp's ridley hook reports was significantly earlier (day 164; 14 June) than for loggerheads (day 199; 19 July; F_1,206 = 21.72, p < 0.0001).

There was a distinct difference in the number and species of turtles hooked, and their distribution among the VAPPP piers. Among the VAPPP piers, nearly two-thirds (n = 144) of the 224 turtles identified to species were Kemp's ridley turtles, 41 (18%) were identified as loggerhead turtles, and 3 as green turtles. Species was not determined for 36 hooked turtles at VAPPP piers. Seven additional Kemp's were hooked at non-VAPPP piers in Chesapeake Bay and 19 turtles (12 Kemp's ridley, 4 loggerheads, 1 green, 2 unidentified) were hooked from shore (beach, bulkhead, bridge) and 7 from vessels. Three of the 7 piers were not open for the entire study period. Of the remaining 4 piers open in all years, 2 were on the ocean coast south of the Chesapeake Bay mouth; Little Island (LI) was the southernmost and Virginia Beach (VB) pier was closer to the Bay mouth. The 2 piers in the bay were located on either side of the entrance to the port of Hampton Roads; Ocean View (OV) was the longest pier in the study and Buckroe Beach (BB), the westernmost and one of the shorter piers. These 4 piers were all manned piers with entry gates and/or personnel in attendance while the piers were open and were responsible for 87% (n = 202 of 231) of the hooked turtles reportedly caught from piers in 2014–2018, with BB having the highest number (n = 67) followed by OV (n = 57), VB (n = 57), and LI (n = 21). When species could be verified among the 4 piers in the VAPPP throughout the study, all but 1 loggerhead was hooked at either OV or BB. Most unidentified turtles (19 of 30) hooked from these piers were reported from OV, followed by BB (6 of 30), and it is likely that loggerheads dominated this group of turtles. The 3 piers in Chesapeake Bay that were not participating for the entire study also had 10 loggerhead reports. Only Kemp's ridley and unidentified turtles were reported from LI, but Kemp's ridley numbers were higher at VB, followed by BB and OV.

All the 170 turtles admitted during the study period were juveniles, with SCL ranging from 19.8 to 49.4 cm for Kemp's ridleys, 44.4 to 69.1 cm for loggerheads, and 25.5 to 31.7 cm for greens. From 2014 through 2018, hooked Kemp's ridley sea turtles measured 32.4 ± 6.7 cm SCL (n = 146, 1 Kemp's ridley had carapace deformation that prevented accurate total length measurements) vs. 33.9 ± 9.1 cm SCL for stranded, nonhooked (n = 25), and there was no significant difference between the 2 groups (W = 1900, p = 0.745). Hooked loggerhead sea turtles measured 58.9 ± 5.9 cm SCL (n = 19), vs. 68.4 ± 9.4.0 cm SCL for stranded, nonhooked (n = 55) and there was a significant difference between the 2 groups (t = 5.171, df = 50.26, p < 0.0001). Hooked green sea turtles measured 28.9 ± 2.9 cm SCL (n = 4), vs. 28.8 ± 2.9 cm SCL for stranded, nonhooked (n = 31), but with 4 hooked green turtles admitted during the study and such similar means, the authors assumed no difference, but did not conduct a statistical test.

Turtle Examination and Assessment. — BCI was calculated for 168 of the 170 hooked turtles examined, including 145 Kemp's ridleys, 19 loggerheads, and 4 greens. Mean BCI for the hooked group was 1.43 ± 0.11 for Kemp's ridleys, 1.59 ± 0.15 for loggerheads, and 1.31 ± 0.15 for greens. BCI was also calculated for live, stranded, nonhooked turtles, including 26 Kemp's ridleys, 40 loggerheads, and 14 greens. Mean BCI for the stranded, nonhooked group was 1.43 ± 0.20 for Kemp's ridleys, 1.39 ± 0.17 for loggerheads, and 1.27 ± 0.09 for greens. There was no significant difference in BCI between hooked and stranded, nonhooked Kemp's ridleys (p = 0.9452, t = 0.069393), but mean BCI was significantly lower in stranded loggerheads than in the hooked group (p < 0.0001, t = 4.5802). Notably, BCI of hooked Kemp's ridleys varied significantly by month (p = 0.0003), with values steadily increasing from April to August. Green turtle BCI data were not tested due to small sample size.

Blood values from the hooked turtle group fell largely within reference intervals, except for albumin values in Kemp's ridleys. Mild hypoalbuminemia was observed compared with published normal albumin values of 1.0 ± 0.3 g/dl (George 1997). Blood albumin values ≥ 1.0 g/dl have been a common clinical parameter used by sea turtle veterinarians to approve animals for release (R. George, pers comm., May 2014). Initial albumin levels often fell below 1.0 g/dl, particularly in animals hooked in the spring and early summer months. Of the 129 Kemp's ridleys with initial albumin values, 60 (85%) fell below the 1.0 g/dl threshold in May and 24 (83%) in June. Albumin varied significantly by month (F_7,121 = 6.6148, p < 0.0001), with levels increasing from April to July, and falling from August through November. Hematocrit did not vary significantly by month during this time (p = 0.7831).

Angler Survey Data. — From 2014 to 2017 volunteers conducted 2036 angler surveys at the 7 partner piers. More than 1600 (79%) of the 2036 individuals or groups surveyed identified themselves as Virginia residents. Virginia anglers listed 115 different cities and counties as their primary residences, and the majority claimed cities/counties near piers in the VAPPP as their primary area of residence (n = 1161, 57%).

Most Virginia anglers who provided information on their fishing frequency reported fishing weekly as compared with daily, monthly, or yearly. Weekly fishing frequency was most reported on all the piers and ranged from a low of 36% (117 of 322) of responders at the OV Pier to a high of 66% at the Engineer Wharf Pier (101 of 152). When surveyed in reference to sea turtle sightings within the 12 mo prior (among anglers who provided an answer), 26% (530 of 2029) reported seeing a sea turtle while fishing, 13% (261 of 2031) reported seeing one caught, and 4% (83 of 2032) reported catching a sea turtle while fishing. While there was a range of answers by pier and month, there were no differences temporally or spatially. However, anglers who reported fishing with greater frequency (i.e., weekly or daily) reported greater incidence of seeing (39%; 364 of 922) and catching (6%; 59 of 927) sea turtles.

Within the 2023 surveys where bait type was indicated, 6 types represented 97% of the primary bait type reportedly used by pier anglers (Table 1). These included, in order of greatest use, squid (29%), cut fish (20%, various species), bloodworms (17%), shrimp (14%), artificial bait (10%, “flavored” substance placed on a hook), and whole fish (8%, live and dead of various species). Of these, squid was the most common in all months except October, when bloodworms and cut fish dominated.

Table 1. Bait types used by surveyed Virginia anglers and during sea turtle interactions. Due to multiple baits used by some anglers during turtle interactions, a total of 236 baits were reported by 219 anglers. Bold type indicates p < 0.01 significance.

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Six hook categories constituted the main hook types used by anglers, including J-hooks, circle hooks, lure and jig, kahle hooks, octopus hooks, and treble hooks. J-hooks and circle hook types were reported by 90% of anglers (Table 2). J-hooks were used by 75% (1507) of anglers who responded to the question. Circle hooks were the second most common hook reported and made up 16% (326 of 2023) of responses. Both J-hooks and circle hooks were most used with squid as bait, but distribution of other bait types differed between the 2 hook types. Using a χ² test, bait used on the 2 hook types differed significantly (χ² = 51.97, df = 4, p < 0.0001). Post hoc comparison using methods explained by MacDonald and Gardner (2000), with a Bonferroni-corrected p-value = 0.005, indicated that significance was due to the difference in use of live fish between the 2 hook types (p < 0.0001 for all 2-way comparisons between live fish and other bait types) with live fish used more frequently on circle hooks than J-hooks.

Table 2. Hook types used by surveyed Virginia anglers and during sea turtle interactions. Due to multiple hooks used by some anglers during turtle interactions, a total of 210 hooks were reported by 193 anglers. Bold type indicates p < 0.01 significance.

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There were 23 different target species identified among 2036 responses, with a 24th nonspecific category (e.g., anything that could be caught), being the most common. The 5 most common target categories included nonspecific (58%; n = 1188), croaker (Micropogonias undulates; 10%; n = 211), spot (Leiostomus xanthurus; 7%; n = 150), cobia (Rachycentron canadum; 6%; n = 114), and drum which included both red drum (Sciaenops ocellatus) and black drum (Pogonias cromis) (6%; n = 113).

Turtle–Gear Interactions. — Of the 250 hooked turtles reported by anglers to VAQS, 233 (94%) hooked a turtle from a pier; 10 (4%) were hooked from shore including beach, bulkhead, rip rap, and a bridge; and 7 (3%) from a vessel. Of the 170 turtles recovered for exam following a hook interaction, lift nets (supplied by VAQS or otherwise) were used in 73% (n = 124) of anglers.

Bait type was reported for 219 events where a turtle was hooked, with respondents reporting using up to 3 bait types during an interaction, resulting in 236 individual baits reported (Table 1). The most encountered bait types were squid (51%), cut fish (25%), and shrimp (12%). The preference for squid was significant when compared with the anglers surveyed, with 29% reporting squid use (χ² = 41.32, p < 0.0001). For the less frequently reported categories of bait, bloodworms, artificial bait, and whole fish appeared to capture turtles less frequently than their ratio of use by the general population of anglers would suggest. Specifically, bloodworms and artificial bait were less frequently used when hook interactions occurred (χ² = 10.312, p = 0.0013 and χ² = 8.4894, p = 0.0036, respectively). Frequency of the 6 most reported categories of bait type were significantly different between the general angling population from surveys and anglers who caught turtles (χ² = 66.574, df = 5, p < 0.0001). Of the 250 reported interactions, bait type was unknown for 31 turtles (12%).

Hook type was identified in 191 of the 250 reports, resulting in 282 recreational fishing hooks being described (some turtles recovered with more than 1 hook, either from the reported incident or a prior interaction). Hooked turtles interacted with 5 different types of hooks (J-hooks, circle hooks, kahle hooks, octopus hooks, and treble hooks), and J-hooks and circle hooks constituted 93% of the hooks (160 and 36, respectively) (Table 2). Frequency of hook types found in hooked sea turtles was compared with usage by surveyed anglers, and J-hooks were more often encountered during turtle interactions (83% vs. 74%, χ² = 6.2403, p = 0.01249). Hook type was unknown for 57 (23%) of the 250 reported interactions, due to hook deformation, removal prior to exam, or lack of data from the angler responsible. Hook measurements were obtained for 50 of the 98 hooks removed and retained from turtles. The measured hooks ranged in maximum length (tip of shaft to bottom of curve) from 14 to 60 mm and approximately half (n = 23) had an obvious offset. Notably, the largest hook (60 mm) was recovered from a Kemp's ridley with an SCL (notch-to-tip) of 26.7 cm.

Of the 170 hooked turtles admitted for examination during the study period, 25 (15%) were found to have ingested at least 2 hooks. Of the 28 additional hooks involved in these interactions, 16 (57%) were only visible upon radiographs. In all but one case, additional hooks were not involved in the reported interaction. Of the 147 Kemp's ridleys sea turtles admitted into rehabilitation, 15 (10%) had additional hooks. Of the 19 loggerheads admitted, 9 (47%) were found to have additional recreational hooks, including 3 turtles with 3 hooks each. This difference in the presence of more than 1 hook between species was significant (χ² = 18.7902, p < 0.0001).

Fair/foul hooking classification was reported for 217 of 250 interactions, with fair hooking events accounting for 75% (n = 162) of interactions where fair/foul hooking was reported. Fair hooking events involved the mouth, in areas involving the oral cavity, tongue, and internal and external mandible and maxillae (n = 98), and esophagus (n = 60%), or specific location was unknown (line visible from ingested hook, n = 4). Foul hooking involved the appendages (n = 41), neck (n = 4), eyes (n = 1), and carapace/plastron (n = 5). When only 1 hook was present and no secondary conditions that would have extended time in rehab were noted, foul-hooked (n = 97) turtles spent less time in rehabilitation (11.2 ± 8.8 d) compared with fair hooked turtles (n = 31), which spent 40.0 ± 78.1 d in rehabilitation.

Several turtles were encountered in multiple hook interactions during the study period. In 2016, a Kemp's ridley was captured at a pier, released from the beach 30 km from the original capture location, and recaptured at a different location, approximately 7 km from the original hooking location within 7 d. Additionally, as of 2019, 5 loggerheads were documented in recapture events, with up to 3 hooks found per interaction. Four turtles were documented in the season following initial documentation, and 1 turtle was documented again 3 seasons after its first interaction. These interactions occurred at the OV and BB fishing piers, with 3 turtles encountered at OV on both occasions, 1 encountered at BB on both occasions, and the remaining encountered at both piers.

DISCUSSION

Recreational Hook and Line Bycatch. — While previous studies of recreational fishery interactions have focused on Kemp's ridley sea turtle bycatch in the GOM, this study includes 3 species—Kemp's ridley, loggerhead, and green sea turtle—bycatch in the mid-Atlantic region. Sea turtle presence in Virginia is seasonal, with most (65%) of recreational interactions reported in May and June, suggesting that turtles utilize foraging areas near fishing piers while migrating into the area during spring and early summer. Although the bycaught turtles examined by VAQS were all considered juveniles based on size, life stage remains unknown for unrecovered hooked turtles which, anecdotally, were primarily larger individuals.

The notable disparity between mean SCL of hooked Kemp's ridleys and loggerheads and their stranded conspecifics is likely explained by the negative bias associated with successfully landing larger sea turtles and thus obtaining length data from larger hooked turtles. Loggerhead sea turtles presented a greater challenge for recovery, as these animals frequently broke the line before a successful landing was made in at least 13 cases. It is highly likely that most of the hooked turtle reports of unconfirmed species where the line was broken or the turtle “self-released” were loggerheads.

During the study period, 1 Kemp's ridley was recaptured at a fishing pier, within a week of the animal's initial capture. The 19 loggerhead hooking events documented included 5 individuals that were encountered twice in Virginia, with 1–3 yrs between interactions. Loggerheads were also more likely to carry multiple hooks than Kemp's ridleys. In 2013, prior to the implementation of the VAPPP, 7 turtles total were admitted post–hook interaction, and all were loggerhead sea turtles, 5 of which had multiple hooks, with up to 4 hooks found per animal (VAQS, unpubl. data, 2013). Although the frequency of loggerhead sea turtles documented with multiple hooks dropped following VAPPP outreach, habituation to feeding from baited hooks at fishing piers may occur in this species in Virginia. Alternatively, loggerheads may be attracted to pier structures, resulting in a higher frequency of opportunistic encounters with baited hooks. Co-occurrence of recreational fishing activity and prey habitat, and/or natural prey such as blue crabs (Callinectes sapidus) being attracted to pier structures presents another potentially confounding variable to determine whether habituated feeding from piers occurs.

Admit radiographs of hooked turtles also revealed that true crab and other natural prey items were visible in the GI tracts of 86% of all turtles examined from 2015 to 2017 (n = 86). For the remaining 12 turtles that were radio-graphed, reviewers could not determine whether dense objects in the GI tract were natural prey. This is most likely because chitin from Atlantic horseshoe crabs (Limulus polyphemus) and smaller pieces of prey were not as easily identifiable on radiographs as intact or nearly intact mollusk shells and decapod crustacean claws and legs. None of the GI tracts examined via radiograph appeared to be empty. Because natural prey items, notably crab, were seldom reported to be used as bait by Virginia pier anglers, this suggests that feeding from baited recreational fishing gear may occur as an opportunistic behavior for some animals. Particularly for Kemp's ridleys, for which only 10% exhibited secondary hooks, bait depredation is likely supplemental to foraging on prey, rather than from a dependence on bait as a food source.

In the northern GOM, the recreational gear interaction increase appears to have been driven by a collapse in natural prey species population and ecosystem damage in the wake of the Deepwater Horizon oil spill (Cook et al. 2020). In that region, 70% of repeated recreational fishery interactions occurred within ≤ 10 km of the original capture location even though most postrehabilitation release locations were ≥ 25 km from the piers with the highest capture numbers. This suggests either a high fidelity to piers or to the area in the vicinity of piers. Declining growth rates in turtles recaptured by recreational fisheries in the northern GOM could indicate that fidelity to fishing piers exposes turtles to nutrient-poor diets due to dependency on bait as forage, suggesting that negative ecosystem changes could shift feeding habits from natural prey to bycatch or fishery-dependent prey. Additionally, this behavior predisposes turtles to increased capture stress, which may exacerbate declining growth rates (Coleman et. al 2016).

In Virginia, turtles captured by recreational anglers appeared to be healthy animals as a group, with few exhibiting health conditions unrelated to the hook interaction. Several health parameters appeared to be seasonally influenced, including albumin values and overall body condition. Although low albumin levels are typically an indicator of poor nutrition (Campbell 2006), the animals in this study presented with low values in the absence of poor body condition, secondary health conditions, or additional aberrant blood chemistry values. Admit albumin values of individual turtles also increased over the course of the season into July, falling again in the late summer and fall months, indicating a temporal trend, rather than static values. Low albumin has been observed by the authors in live captured research subjects encountered in Virginia in late April and early May, again with no other abnormal blood values (VAQS, unpubl. data, 2013). The working hypothesis for low albumin in these animals, considered healthy by NMFS research guidelines, was that recent migrants to Virginia likely shift to foraging behavior from migratory behavior during this time, experiencing periods of exertion and less intense feeding while doing so. Hematocrit, of which low values may also indicate poor nutrition or illness, did not vary significantly temporally. Coleman et al. (2016) found similar consistency in hematocrit values, suggesting that hematocrit may be a more informative diagnostic value than blood albumin in the assessment of presumed healthy animals, especially when turtles are encountered in temperate habitats. BCI values also support the hypothesis that hooked sea turtles in Virginia were generally healthy. Data used for BCI should, however, be species and regionally specific especially when considering migration into temperate habitats. Size and time of year may also affect the normal range of BCI values for juvenile life stages of smaller species such as the Kemp's ridley.

Angler Surveys. — Nearly all anglers were willing to participate in surveys. Compiled data from the angler surveys conducted at piers showed that most pier anglers lived near the piers where they fish, and that many frequented piers on a regular basis. These data, along with increased numbers of hooked-turtle reports as survey effort and the authors' personal experience and communication with anglers who hooked turtles increased, suggest an interested group of stake holders willing to receive and act on outreach messages. With more than 2000 surveys conducted across a range of months when sea turtles appear in Virginia waters, the authors feel comfortable that the compiled data represent a cross-section of the recreational hook and line fishery as conducted from piers in the region.

As a group, pier anglers in Virginia primarily targeted anything they could catch (nonspecific), bottom-feeding sciaenids such as spot, croaker, and drum, or specialized on mid- and top-water feeders such as cobia. Results of the angler surveys at piers compared with interviews of anglers who hooked turtles suggest that the fishing practices of anglers who hooked turtles were like those in the general pier angler population.

There was a slight difference in ratio of J-hooks and circle hook types, with J-hooks found more frequently in the hooked-turtle group than reported by surveyed anglers. However, the proportionately large number of turtle interactions where gear type was unknown (n = 57) and the large angler survey sample size diminish the significance of this finding. Also notable, J-hooks typify the type of widely available and inexpensive tackle available to anglers in the study.

Although bait types ranked similarly between the 2 groups of anglers, a significant disparity existed in the form of preference for squid (ranked first) and less-preferred bloodworms (fourth) and artificial bait (fifth). Cut fish, which was a possible bait preference identified by Cook et al. (2020), was present in a similar ratio among the general angler surveys (20%, ranked second) and anglers who hooked turtles (25%, ranked second). Shrimp as a bait type, which Cook et al. (2020) found more frequently among the general population than among anglers who hooked turtles, was also used similarly between the 2 groups in our study with 14% (third) and 12% (third) respectively.

Effectiveness of Outreach. — Following the inception of the VAPPP, the number of reported recreational fishery interactions steadily increased annually through the reporting period, presenting a valuable opportunity to better characterize these previously underreported events. Data from recreational fishery surveys in Mississippi also suggested that educational outreach was a major contributing factor to increased reporting of recreational hook and line bycatch (Coleman et al. 2016; Cook et al. 2020). In this area, both survey and outreach effort decreased in 2019, and 29 hooked turtles were reported that year, a decrease in number by more than half compared with the previous year (see Table 1; VAQS, unpubl. data, 2013).

Importantly, engaging the recreational fishing community through targeted education and outreach may provide the most important step in mitigating severity of injuries to sea turtles. The authors believe that general familiarity with rescue procedures, adoption of safe landing techniques, and prompt reporting mitigated further injury of hooked turtles and enabled VAQS to recover a greater proportion of hooked turtles for exam with the inception of an outreach program than prior to targeted outreach.

Lift net usage was an essential component of hooked sea turtle outreach and rescue, and should be encouraged for use by the fishing public. The use of both VAQS-provided and personal lift nets allowed anglers to respond promptly to a hook interaction by confining the turtle in the net quickly, thus reducing tension on the hook and injury site, preventing further injury or release with trailing line. Additionally, establishing secure areas to contain turtles awaiting pickup by the rehabilitation organization, such as a tackle shop or pier office, reduced handling and likely the stress experienced by individual animals. Additionally, engaged pier staff helped enforce reporting and could also collect basic information about the interaction, which was extremely helpful when anglers left the pier before responders were contacted or otherwise declined an interview. This type of engagement was possible because most of the piers in the VAPPP had controlled access and manned gates. Coordination of response, animal holding/transport, and data collection/ angler interviews was considerably more difficult at the locations without management.

Beyond measures for reducing further injury in hooked sea turtles, interaction mitigation measures remain unclear and require further study and supporting data prior to developing recommendations for tangible preventative measures. Preliminary data of bait preference observed in hooked turtles suggests a generalist feeding behavior reflective of the bait used at fishing piers, except for disparities in preferences (of varying significance) for some bait types. However, a directed, experimental study of various factors contributing to interactions with hook and line gear may better address measures for mitigating interactions.

Recreational Bycatch as a Threat to Sea Turtle Populations. — Previous studies of sea turtle interactions with commercial longlines, and freshwater turtle taxa interactions with recreational anglers demonstrate hook and line gear can be a significant threat to both individual animals and turtle populations (Casale et al. 2007; Enge et al. 2014; Nemoz et al. 2004; Steen et al. 2014; Steen and Robinson 2017Swimmer et al. 2014; Wallace et al. 2013). Depending on the size of the turtle relative to an ingested hook, the risk for injury may be great, especially for smaller-bodied animals like Kemp's ridleys, which appear to be disproportionately encountered by recreational anglers, in the northern GOM and Virginia. Recreational hook ingestion can cause perforation of the esophagus and nearby heart and great vessels, as well as lower GI tract perforations resulting in coelomitis and septicemia, often-fatal conditions (Orós et al. 2004, 2005; Parga et al. 2012).

The 2 deaths of hooked turtles observed while in rehabilitation resulted from hook trauma that perforated the esophagus, with no lift net used in either recovery. Due to the height of many fishing piers, substantial lengths of trailing line may remain with a hooked turtle after breaking the line or line being cut by the angler, resulting in fatal conditions similar to those described in longline fisheries. Additionally, VAQS has documented recreationally hooked turtles that have subsequently become entangled in pier pilings because of the trailing attached gear, as well as individuals suffering fatal asphyxiation from neck entanglement and septicemia following limb entanglement.

Sublethal and cumulative effects, including the stress of capture and subsequent handling, may negatively impact hooked sea turtles, but these effects are intrinsically difficult to measure. While many of the interactions documented in Virginia were sublethal in the short term, the long-term effect of the recreational hook and line fishery may be significant, at least to the portion of the Kemp's ridley population that occurs seasonally in Virginia. Further, underreporting at piers, as well as unexplored avenues of recreational fishing, such as private fishing piers and shore- and boat-based fishing, means the numbers reported here may represent a small percentage of the actual bycatch. Due to the implementation of the VAPPP soon after observing an increase in reports of hooked turtles and few observed recaptures in Virginia, limited data exist to compare pre- and postoutreach outcomes. Long-term data and future study will continue to provide insight into managing the complex nature of sea turtle bycatch in the hook and line fishery.

CONCLUSIONS

These data provide an indelible link between sea turtles and the saltwater recreational hook and line fishery in Virginia. The relatively recent literature documenting recreational bycatch and the dramatic increase in reports of such interactions, when coupled with targeted outreach, suggest the scope of this bycatch is grossly underreported. The resulting interactions may present a particular threat to critically endangered Kemp's ridley sea turtles, as they comprise the majority of reported interactions in the lower Chesapeake Bay and southeast Atlantic coast of Virginia. Regardless of the factors that influence the rate of interactions between turtles and recreational fishing gear, sea turtle habitat use and recreational fishing overlap both seasonally and geographically, and interactions are expected to continue. Ultimately, many aspects of these interactions are difficult to control, and potential effectiveness of bycatch mitigation measures remains unclear. This is exacerbated by limited federal regulatory control of the recreational fishery and resource limitations for states and nongovernmental organizations to consistently document the issue, despite recent development of a standard format for documentation of angler–turtle interaction data (Cook et al. 2020).

The uncertainty of the long-term effects resulting from these interactions will further stay the impetus for regulatory control with the limited data available. The evidence documenting the risk of serious injury and mortality in loggerhead interactions with commercial longline operations may provide a bleak parallel for the risks encountered by Kemp's ridley sea turtles in the recreational fishery without mitigation efforts. As opposed to regulatory change, for which there appears little consistent political interest, outreach and voluntary behavioral changes are measures that are more likely to be accepted and implemented by many recreational anglers. Effective engagement with the recreational community also provides the most direct approach to injury mitigation, and any further bycatch mitigation measures should involve this community. Continued outreach, education, and data collection efforts such as these require resources, especially funding, that have not been readily available. Interactions and subsequent injury and mortality are therefore expected to continue, and so future studies to improve hook detection and removal techniques, provide supportive care, and investigate postrelease success remain warranted, as these measures are within the immediate control of the responding agencies, like VAQS, on the receiving end of hooked sea turtles.