Stingray and Shark Tagging Analysis in Promotion of Population and Ecosystem Conservation: Alabama, Florida 2015-2018 Project Report

Stingrays and sharks are linchpin species that help maintain the function and stabilization of local bay systems. A three-year tagging project was designed and implemented in an effort to gather migration and habitat data of target species. Seventy-two specimens were tagged using labeled, plastic anchor tags placed in the medial pectoral radials for rays and adjacent the dorsal fin for sharks. To date, tagged stingrays have a 0% return, sharks have a 12.5% return. Continued research is needed for a more complete understanding of their population dynamics in the promotion of on-going conservation efforts.


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Permitted Alabama Species
Species that were not allowed to be tagged in Alabama waters were species that are listed by the United State Fish and Wildlife Service (USFWS) as Threatened or Endangered (T&E). No species that were targeted for tagging are listed by the USFWS. Alabama does not list any stingray or shark as being a T&E species at the state level. All stingray or shark species caught in Alabama waters were eligible for tagging.

Permitted Florida Species
Only specific stingrays and sharks were permitted for tagging in Florida waters, regardless of the federal status. The permitted species are listed on the SAL permit and are depicted in Table 1.
Tagging was only permitted in the following Florida counties: Bay, Broward, Duval, Escambia Hillsborough, Nassau, Palm Beach, Pinellas and Walton counties. A 24-hour notice was required to be given to the FWC Division of Law Enforcement prior to any tagging.

Stingray and Shark Acquisition
Acquisitions of the target species were through the combination of recreational shrimp trawling, as well as, hook and line recreational angler abandonment.

Recreational Shrimp Trawling
Two recreational shrimp charter services were employed during the research timeframe.

Recreational Sport Fishing
Two permitted anglers in Florida tagged sharks and stingrays. While stingrays are unregulated in Florida, any rays outside the default bag limit of two specimens or 100 pounds, would be considered abandoned (FWC, n.d.). Abandoned rays were tagged and returned to the water. Shark fishing is regulated in Florida. "The daily bag limit is one shark per person per day and there is an overlapping vessel limit of two sharks" (FWC, 2013, Para. 5). The water depths of specimens caught ranged from 15ft. to 50ft. Hook and line rigging as highly variable, but anglers were licensed per state. All rays and sharks tagged in Florida waters were from angler abandonment, no trawling was performed.

Tags and Tag Placement
All tags deployed were T-bar anchor tags, except for two dart tags. The tags are made by Floy Tag and Manufacturing, Inc. The most deployed tags was a 3" monofilament (FD-94) with a hot pink polyolefin Shrink-Lock TM tube covering; printed with the www.Stingray-Tagging.com website address and a consecutive identifier number. The tags are administered with an Avery Mark lll tagging gun ( Figure 1).
A larger, 4" neon green T-bar tag (FD-94) was used on sharks #103 -#105, and a smaller, 1" blue T-bar tag (FF-94) was used on small rays (< 9" in wing width). The FF-94 tags were administered with a Mark lll fine fabric gun. Both of these tag types were also imprinted with the website and identifier number. The two dart tags (FT-1-94) were a 4" neon green filament imprinted with the website and identifier number.

Tagging Stingrays
A strict tagging protocol was followed in an effort to decrease harm to specimens. Once the rays were removed from the trawl net, they were immediately put into a plastic container of bay water to await tagging. Upon selection for tagging, the ray was moved to a tagging container that allowed for data collection, such as wing measurements, health assessment, and sexing ( Figure 2). Data pertinent to water salinity and the weather were also recorded on each specimen's field tagging data sheet. The weight of each ray was not recorded in the field. In effort to avoid injury to the ray and the tagger when trying to weigh a specimen, the Length/Weight Conversions for Marine Fishes of Texas website (http://txmarspecies.tamug.edu/length-weight.cfm) was used during entry of field data into the Excel database.  Each ray was visually assessed for the best tag insertion location. "Determining the proper placement of the T-bar anchor tag in the pectoral fin of the Atlantic Stingray is important to ensure the longevity of the tag" (Lahn, 2017). The best section of the fin for tag insertion is the mid-line medial radials. Placing the tag a quarter of the total length to the anterior or posterior the mid-line would also be acceptable due to the radial calcification and their ability to resist pull through. Placement in this area of the wing allows full locomotion, which promotes ray longevity (Lahn, 2017). Tags were placed in either the left or the right pectoral fin. Tags were not placed in injured fins.

Tagging Sharks
The National Marine Fisheries Service (NMFS) shark tagging protocol and data collection was followed when tagging of any specimen of permitted shark. According to the NMFS tagging regime, "the ideal location on large sharks is in the muscle at the very base of the first dorsal fin" (NMFS, 2018).
While sharks were not the focus of the research project, any permitted sharks that were considered angler abandonment were tagged. After landing a shark, it would be identified (genus and species) and checked against the FWC SAL list if caught in Florida waters. Field data such as length, width, sex, and health assessment were recorded on the field data log.
All sharks, but two, were tagged at the base of the dorsal fin with T-bar anchor tags ( Figure 3). Two sharks were tagged with dart tags at the base of the dorsal fin. Unhealthy or injured sharks were not tagged.

Result
The total of 11 tagging expeditions were completed during the permitted timeframe, for an average of 3.66 per permit year. Each expedition lasted at least three hours. Terry Cove, AL was the predominant bay with 47-tagged rays. The next common water body was Perdido Pass with 11 tags and Wolf's Bay with 10 tags. The most prolific month for tagging was November with 38-tagged specimens followed by December with 11 individuals. It is not believed that these tagging numbers are a reflection of monthly populace as there are researcher constraints on tagging during summer months. A full log of tagging bays and dates can be reviewed in Table 2.
The most tagged stingray was the Atlantic stingray. A total of 51 D.sabina were tagged, with all specimens being caught and returned to waters of Alabama. The next abundant ray tagged was the Cownose ray, with eight individuals tagged followed by two tagged Southern stingray. The Smooth Butterfly ray and the Lesser Electric ray were each tagged once for a total of 64 rays being tagged. The average number of rays tagged per trip was 5.81. Two Sandbar sharks and one Tiger shark were tagged in Alabama waters. One Atlantic Sharpnose shark, two Blacktip sharks, and two Spinner sharks were tagged in Florida waters. Total specimens tagged in all waters are 72. GPS locations of each specimen tagged are available in Table 2.

Return Tags
Only one tagged individual from the 2015-2018 Alabama, Florida tagging project was a viable return.

Discussion
There were multiple successes, areas of improvement and project adversities that are worth review.
Issues with tag longevity and the lack of stingray returns are the top concerns.

Tag Longevity
To date, the longest a 3" monofilament (FD-94) tag has lasted is one year, four months and nine days.
After the condition of tag #35 was reported as highly corroded and fell off the specimen, a thicker tag (FT-1-94) was used for additional shark tagging. The effort output for tagging sharks versus length of viable tag time makes the FD-94 unsuitable for continued shark tagging. It should also be considered that the FD-94 tags are not suitable for long-term tagging of any saltwater species.

Stingray Returns
There are no stingray returns to date. This can be attributed to several factors. The sheer volume of stingrays present in the tagging bays could mean that the tagged rays have not been recovered amid the large population. The lack of returns may also be due to the FD-94 tags not holding up to the stingrays' natural burrowing instincts and therefore FD-94 tags have a very short lifespan. There is also heavy

Tagging Success
Using recreational shrimping charters offered the best way to acquire stingrays, although it is considered high effort (charter cost, physical output, etc…). Netting the rays also decreased potential injury to the ray versus a hook and line catch. Shrimp charters also operate during peak stingray season, which made chartering easy. The on-vessel method of using water-filled containers while gathering data and tagging, also contributed to the decrease in potential ray stress.

Angler Abandonment
Angler abandonment was successful when anglers had a tagging interest, but that interest waned over time. It does not appear that using permitted angler abandonment would lead to significant data collection. A better approach to angler abandonment tagging would be to seek out anglers in a concentrated area, such as a pier or beach, and offer to tag their abandonment.

Conclusions
Stingrays may be a linchpin species between trophic regimes and their persistent populations help maintain the function and stability of our local bay systems. It was hoped that tagged specimens could be tracked and then contribute data for several years, but the tagging data thus far does not support this.
It is possible that some tagged rays could be returned and if so, updated return percentages will change.
Any tagging in the future will entail using tags with a longer viability range. Angler abandonment should also be approached from a group concentration rather than an individual basis. While tagging specimens for research can be intriguing, dedication to the project from individual anglers fades quickly.
Although there were some limitations on the initial tags used during the project, the overall project contributed to knowledge of the stingray and shark species in the Alabama/Florida coast systems. The human influence of over-fishing and biodiversity loss can affect the stingray and shark populations, as well as their environmental niches. Understanding potential specie regime shifts is an important factor due to it occurring at the regional level with wider geographical implications (Collie et al., 2004). The result of a regime shift, potentially due to overfishing of stingrays and sharks, could lead to a reconfiguration of ecological states (Andersen et al., 2009). Those new regimes may not be as advantageous to human occupancy or commercial endeavors. Any data that expands our awareness of the ecosystem and the interconnected species that rely on it, the better position we will be in to safeguard their populations.