2024-12-12 マサチューセッツ大学アマースト
Researchers read the tag in a giant trevally that had been previously caught. Credit: Alphonse Fishing Company
<関連情報>
- https://www.umass.edu/news/article/uncovering-hidden-consequences-catch-and-release-sport-fishing
- https://cdnsciencepub.com/doi/10.1139/cjfas-2023-0329
- https://www.sciencedirect.com/science/article/abs/pii/S016578362200114X
- https://www.sciencedirect.com/science/article/abs/pii/S0964569121001654
釣り針の向こう側:キャッチ・アンド・リリースのレクリエーション漁業における釣り人と魚の相互作用は、魚の空間利用や釣りやすさを変えるか? Beyond the hook: do angler-fish interactions in a catch-and-release recreational fishery modify fish space use and catchability?
Lucas P. Griffin, Gail Fordham, George Curd, Pierre André Adam, Christopher Narty, Keith Rose-Innes, Devan Vd Merwe, Eleanor Brighton, …
Canadian Journal of Fisheries and Aquatic Sciences Published:12 December 2024
DOI:https://doi.org/10.1139/cjfas-2023-0329
Abstract
By combining acoustic telemetry, mark-and-recapture, and location-specific catch logs, we tested whether angler-fish interactions altered the behavior, space use, and catchability of giant trevally (Caranx ignobilis) (GT) in coastal waters of the Alphonse Island Group, Seychelles, Indian Ocean. Adult GT near a high human use area with limited provisioning showed restricted movements during the tourism fishing season and had home ranges nearly 50% smaller than that of adult GT from other parts of the atoll group. Despite angler catch maps overlapping with 30% of non-habituated adult GT core use areas, recaptures were infrequent, suggesting that GT became hook shy. Although there was no change in movement patterns during a temporary fishing closure caused by COVID-19, non-habituated GT movement patterns shifted toward wider ranging movements with each successive fishing season, potentially to avoid shallow water areas where angler activities occurred. Our findings highlight how angler interactions and catch-and-release fisheries have the potential to modify the behavior, space use, and catchability of targeted species, and may influence the viability of the fishery by exceeding its capacity.
西インド洋、セーシェル共和国、キャッチ・アンド・リリースのフライフィッシング・レクリエーション漁業における、捕獲とハンドリングに対するギンガメアジ(Caranx ignobilis)の短期的反応。 Short-term response of giant trevally (Caranx ignobilis) to capture and handling in a catch-and-release fly fishing recreational fishery, Republic of the Seychelles, Western Indian Ocean.
Lucas P. Griffin, Gail Fordham, George Curd, Christopher Narty, Pierre-André Adam, Jacob W. Brownsombe, Steven J. Cooke, Andy J. Danylchuk
Fisheries Research Available online: 27 April 2022
DOI:https://doi.org/10.1016/j.fishres.2022.106337
Highlights
- Giant trevally support a growing catch-and-release recreational fishery.
- Giant trevally were resilient to capture and handling via fly fishing.
- Minimal behavior impacts will contribute to effective management.
- Longer-term studies are needed on other angling-based disturbances.
Abstract
Giant trevally (Caranx ignobilis, GT) are growing in popularity as a target for tourism-based recreational fisheries throughout their range in the Indo-Pacific. Although predominately catch-and-release (C&R), to date there is no species-specific scientific evidence to support capture and handling guidelines. As such, we examined how GT caught via fly fishing gear while in shallow water responded to capture and handling in the Alphonse Island Group, Republic of the Seychelles. Specifically, we evaluated the physical injury for GTs captured via fly fishing gear, as well as their reflex impairment and post-release activity (using tri-axial accelerometer biologgers) following three air exposure treatments (0 s, 15 s, 30 s). We also had a reference treatment where GTs were caught and landed quickly via a handline, and not exposed to air (0 s) prior to release. Hooking location for both gear types was predominately the jaw or corner of the mouth (fly fishing, n = 30; 83.3%; handline; n = 12, 85.7%), but one fish hooked in a critical location for each capture gear. Across all treatments, only one fish (2%) in the handline treatment was considered a potential short-term post-release mortality following being deeply hooked in the gills and subsequently losing equilibrium upon release. GT reflex impairment and overall post-release activity measured via overall dynamic body acceleration were not influenced by fight time and air exposure treatments used in our study. For GTs across all treatments, locomotor activity was lower in the initial minutes following release than during the second half of the ten minute monitoring period. Overall, our study suggests that GTs in the Alphonse Island Group are resilient to being caught via fly fishing, handled, and air exposed for up to 30 s. However, given the diversity of angling locations for GTs (e.g., shallow flats, deeper reefs) and gear types (e.g., conventional tackle, lures with several treble hooks), additional assessments are needed to help act as the foundation for more universal best practices that can inform management plans for GT recreational fisheries.
セーシェル、アルフォンス島群におけるキャッチ・アンド・リリースの遊漁のための協力的モニタリング・プログラム: データ不足から科学と管理の基盤へ。 Cooperative monitoring program for a catch-and-release recreational fishery in the Alphonse Island group, Seychelles: From data deficiencies to the foundation for science and management.
Lucas P. Griffin, Pierre-André Adam, Gail Fordham, George Curd, Caitlin McGarigal, Christopher Narty, Josep Nogués, Keith Rose-Innes, Devan Vd Merwe, Sascha Clark Danylchuk, Steven J. Cooke, Andy J. Danylchuk
Ocean & Coastal Management Available online: 11 May 2021
DOI:https://doi.org/10.1016/j.ocecoaman.2021.105681
Highlights
- Remote tourism-based catch-and-release recreational angling ventures are emerging.
- Baseline fisheries data is often lacking but needed for sustainable use.
- Catch log data provided spatially explicit maps of high-pressured fishing areas.
- Monitoring by stakeholders provides foundation for evidence-based management.
- Data collection may be inhibited due to competing demands with monitoring programs.
Abstract
Recreational fishing is a growing sector of tourism, and in theory, can be done in a sustainable manner such as through catch-and-release where fish are released rather than harvested. In some cases, stakeholders have taken the initiative to develop conservation strategies and management guidelines, as well as establishing monitoring programs of the resources they use. In this work, we provide a case study of a cooperative monitoring program in the Alphonse Group, Republic of the Seychelles, Africa, between a fishing company (Alphonse Fishing Company) and a local non-governmental organization (Island Conservation Society). These efforts have resulted in a code of conduct for the catch-and-release of target species, as well as long-term spatially explicit monitoring of catches, including fish size and catch location for five popular species through catch logs. During three seasons, the five key fish species monitored were giant trevally (Caranx ignobilis, n = 684), moustache triggerfish (Balistoides viridescens, n = 141), Indo-Pacific permit (Trachinotus blochii, n = 99), milkfish (Chanos chanos, n = 55), and yellowmargin triggerfish (Pseudobalistes flavimarginatus, n = 46). We found monthly catch variability across all species and that catches across seasons increased for C. ignobilis (203.8%), T. blochii (45.5%), and B. viridescens (25%), and decreased for C. chanos (-65.6%) and P. flavimarginatus (-10%). Although there are considerations with implementing and maintaining such initiatives, we reviewed the benefits, including how these efforts can serve as the foundation for more thorough scientific research, co-production, and evidence-based management for the most sought-after species, C. ignobilis. We highlight how these cooperative initiatives may lead to formal co-management structures in recreational fishing, and also help to build capacity in government agencies for advancing economic prosperity while establishing sound long-term management and conservation strategies.
