Project Seahorse researcher Allison Stocks (@Ally_Stocks) investigated the impact of small-scale fisheries on local seahorse populations in southern Vietnam.
A major supplier of seahorses in global trade, Vietnam struggles to manage its seahorse fisheries. In 2014, the country was banned under CITES from exporting Hippocampus kuda, a seahorse species listed as ‘Vulnerable’ on the IUCN Red List. Vietnamese seahorse fisheries operate using small trawl boats to catch a number of different, vulnerable species that are then sold on the local and international markets, primarily for use in traditional medicines. Understanding the impact of these fisheries is key to improving trade regulations for Vietnam.
The findings of Ally's work will inform a national management plan for Vietnamese seahorse fisheries, with the ultimate goal of increased protections for these iconic species.
My research focuses on garnering some of the much-needed biological, fisheries and trade data that will enable Vietnam to keep its seahorse populations sustainable in the wild. Seahorses are caught both intentionally and as bycatch in fisheries throughout Vietnam – but none of this catch is monitored or regulated. This has made it incredibly difficult for Vietnam to ensure that seahorse trade (which is supplied by seahorse fisheries) is sustainable. As a result, exports of Hippocampus kuda are banned from Vietnam. However, seahorses continue to be fished along Vietnam’s coastline, and exports of six other seahorse species (Hippocampus comes, H. histrix, H. kelloggi, H. mohnikei, H. spinosissimus, and H. trimaculatus) are still permitted.
I investigated a fishing area in the Gulf of Thailand from April to July 2014 with two major research goals:
1) To investigate historical changes in the fishery.
2) To determine the catch rates of different fishing gears (the number of seahorses they catch per day) and the total annual catch.
1) Understanding the fishery and changes that have occurred
To understand if there have been changes over time in seahorse catches, we conducted semi-structured interviews to document fisher understanding of the biology, fishery, trade, conservation and management of local seahorses. We collected data on five fishing gears: otter trawls, beam trawls, crab nets, compressor diving, and pair trawls. We documented fishers’ perceptions of past and present seahorse catch rates to model any changes that may have occurred in the fishery.
2) Quantifying fishing pressure
To determine the catch rates of different fishing gears, on a near-daily basis we sampled seahorse catches from fishing ports across Phu Quoc and the An Thoi islands. During these surveys we documented fishing gear, capture method (intentional or bycatch), fishing location, and species, size, sex and reproductive status of seahorses. This data revealed high catch areas, high impact gear types, and sex- or size-specific pressures of different gears on seahorse populations.
This research has generated information on both seahorse life history and exploitation in Southern Vietnam and is the first wild seahorse life history data collected in these waters. The data will be provided to Vietnamese authorities and will increase capacity for sustainable management and conservation of these vulnerable marine fishes.
Images from the field
Stocks, A. P., S.J. Foster, N.K. Bat and A.C.J. Vincent. 2017. Catch as catch can: Targeted and indiscriminate small-scale fishing of seahorses in Vietnam. Fisheries Research 196:27-33.
Bach Dang, N., Momtaz, S., (2015). The contributions of fishers’ knowledge to marine fisheries management: A case study of a coastal commune in Vietnam. First Asia Pacific Conference on Advanced Research. p. 12.
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Giles, Brian G., Truong Si Ky, and Amanda CJ Vincent (2006). "The catch and trade of seahorses in Vietnam." Biodiversity & Conservation 15.8: 2497-2513.
Hauck, M., (2008). Rethinking small-scale fisheries compliance. Marine Policy 32, 635–642.
Meeuwig, J. J., Ky, T. S., Job, S. D., & Vincent, A. C. (2006). Quantifying non-target seahorse fisheries in central Vietnam. Fisheries Research. 81.2: 149-157.
Nguyen Van Long and Do Huu Hoang (1998) Biological parameters of two exploited seahorse species in a Vietnamese fishery. The Marine Biology of the South China Sea.
Pomeroy, R., Thi Nguyen, K.A., Thong, H.X., 2009. Small-scale marine fisheries policy in Vietnam. Mar. Policy 33, 419–428.
Vincent, A. C. J., Foster, S. J., & Koldewey, H. J. (2011). Conservation and management of seahorses and other Syngnathidae. Journal of Fish Biology. 78.6: 1681-1724.
Vu Ngoc Ut and To Cong Tam (2012). Species composition and fishing status of seahorse (Hippocampus spp.) in Phu Quoc Island, Vietnam. Proceedings of International Conference, Bien Dong, Vietnam.