Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
North Carolina ◽  
Fishery Management ◽  
Management Plan ◽  
Atlantic Sturgeon ◽  
Alosa Sapidissima ◽  
Management Measures ◽  
Cape Hatteras ◽  
Stock Information ◽  
Mixed Stock ◽  
Acipenser Oxyrinchus

<em>Abstract.</em>—Declines in Atlantic sturgeon <em>Acipenser oxyrinchus</em> abundance in the early 1990s led the Atlantic States Marine Fisheries Commission (ASMFC) to prepare a mandatory fishery management plan. The principal management measures are fishery closure, bycatch assessment, and bycatch reduction in other ASMFC-managed fisheries (i.e., American shad <em>Alosa sapidissima</em>). To better understand Atlantic sturgeon geographic distribution and habitat use, as well as risk of bycatch, we examined offshore distribution of Atlantic sturgeon based on incidental captures in winter tagging cruises conducted off the coasts of Virginia and North Carolina, including in and near extensive sand shoals adjacent to Oregon Inlet and Cape Hatteras. From 1988 to 2006, 146 juvenile Atlantic sturgeon were captured by bottom trawling in depths from 9.1 to 21.3 m. Numbers of Atlantic sturgeon captured and tagged in a given year ranged from 0 (1993, 1995) to 29 (2006). Atlantic sturgeon were encountered in 4.2% of tows, with the percentage varying from 0 in 1993 and 1995 to 12.6% in 1988. Capture patterns suggested that Atlantic sturgeon were likely aggregating to some degree. Total lengths of captured Atlantic sturgeon ranged from 577 to 1,517 mm (mean of 967 mm), suggesting that most fish were juveniles. Limited tag returns and genetic data suggest that fish wintering off North Carolina constitute a mixed stock. Information about their distribution and habitat utilization should benefit fishery managers seeking to reduce bycatch and protect key habitats.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Large Scale ◽  
Atlantic Coast ◽  
The United States ◽  
Management Plan ◽  
Commercial Fishing ◽  
Atlantic Sturgeon ◽  
Coastal Fisheries ◽  
Number Of Factors ◽  
Acipenser Oxyrinchus ◽  
The U.S

<em>Abstract.</em>—Large-scale commercial fisheries for Atlantic sturgeon <em>Acipenser oxyrinchus</em> in the late 1880s eventually led to substantial reductions in the population size. The coastwide Atlantic sturgeon population of the United States has not recovered to the levels seen prior to the 1900s. A number of factors have contributed to the slow recovery or continued decline of Atlantic sturgeon populations, including continued commercial fishing and the targeting of females for caviar, bycatch in other fisheries, and changes in habitat due to dam construction and water quality degradation. The Atlantic States Marine Fisheries Commission (ASMFC) developed the first coastwide management plan for Atlantic sturgeon in 1990. In response to the shortcomings of that plan, the ASMFC applied new standards and the authority granted to it by the U.S. Congress to adopt a coastwide moratorium on all harvesting in 1998. A federal status review conducted in 1998 concluded that the continued existence of Atlantic sturgeon was not threatened given the situation at the time. Since then, monitoring programs have indicated varying levels of relative abundance in several water bodies along the Atlantic coast. The U.S. government is responsible for undertaking a status review to document any changes since the last review and determining whether those findings warrant a threatened or endangered listing for the species. The government’s findings may have far-reaching effects on many other Atlantic coastal fisheries.

scholarly journals Histology of Tritia mutabilis gonads: using reproductive biology to support sustainable fishery management

2021 ◽  
Vol 34 ◽  
pp. 6
Author(s):  
Alicia Mallet ◽  
Jean-Yves Jouvenel ◽  
Morgane Broyon ◽  
Nelly Pirot ◽  
Benjamin Geffroy
Keyword(s):  
Reproductive Biology ◽  
Fishery Management ◽  
Shell Height ◽  
Management Plan ◽  
Small Scale ◽  
Breeding Period ◽  
Management Measures ◽  
Baseline Information ◽  
Sustainable Fishery ◽  
First Maturity

The mutable nassa, Tritia mutabilis, a marine gastropod that is widely exploited on the Adriatic coast is an important source of income for small-scale fishermen in the Mediterranean Sea, particularly in the Gulf of Lion. However, the lack of knowledge on the ecology and biology of this species limits our capacities to propose and produce an effective management plan. As a result, stocks are currently declining, especially in Italy. In order to optimize a management plan for this fishery, we designed a study to better characterize the reproductive biology of T. mutabilis, using gonad histology and performing a regular monitoring of population size frequency. The average shell height of individuals during the breeding period was 24 ± 2.7 mm for males and 30 ± 3.7 mm for females. The presence of small females (10 mm) and large males (32 mm) in the whole sample challenged previous assumptions regarding protandry (sex change from male to female). The size at first maturity was estimated for males and females at 17.5 mm and 24.4 mm shell height, respectively. In Italy, current management measures include a minimum conservation reference size of 20 mm in shell height. Therefore, it is likely that many individuals that did not reproduce are being caught, which could partly explain the decline observed, despite conservation measures introduced more than ten years ago. Overall, our study provides some baseline information to establish, in consultation with fishermen, management measures for this small-scale fishery in France.

scholarly journals Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2192 ◽  
Author(s):  
Juan C. Levesque ◽  
Christian Hager ◽  
Eric Diaddorio ◽  
R. Jason Dickey
Keyword(s):  
North Carolina ◽  
Water Depth ◽  
Commercial Fishing ◽  
Fishing Gear ◽  
Primary Concern ◽  
Atlantic Sturgeon ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Beneficial Impact ◽  
Acipenser Oxyrinchus

Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given this conservation and management need, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon incidental encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 39.6% and 60.9%, respectively. Our design entangled 51.6% fewer southern flounder, which corresponded to a 48.9% reduction in total weight; the modified gear entangled slightly larger southern flounder than the control gear. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper (5.1–6.3 m) than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. Most southern flounder (n= 518, 39.7%) were taken at a water depth between 3.76 and 5.0 m. This observation suggests that southern flounder prefer slightly shallower waters than Atlantic sturgeon.

scholarly journals Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA)

2016 ◽  
Author(s):  
Juan C Levesque ◽  
Christian Hager ◽  
Eric Diaddorio ◽  
R. Jason Dickey
Keyword(s):  
North Carolina ◽  
Commercial Fishing ◽  
Fishing Gear ◽  
Primary Concern ◽  
Atlantic Sturgeon ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Beneficial Impact ◽  
Fishery Interactions ◽  
Acipenser Oxyrinchus

Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given the need to reduce commercial fishery interactions, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 49.4% and 60.9%, respectively. We also found the modified gear entangled 51.6% less southern flounder, which corresponded to a 32% reduction in total weight; the experimental sections entangled slightly larger individuals than the control sections. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. In addition, we found that 41% of the Atlantic sturgeon encountered were in warmer (26‒30°C) than colder water.

scholarly journals Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA)

2016 ◽  
Author(s):  
Juan C Levesque ◽  
Christian Hager ◽  
Eric Diaddorio ◽  
R. Jason Dickey
Keyword(s):  
North Carolina ◽  
Commercial Fishing ◽  
Fishing Gear ◽  
Primary Concern ◽  
Atlantic Sturgeon ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Beneficial Impact ◽  
Fishery Interactions ◽  
Acipenser Oxyrinchus

Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given the need to reduce commercial fishery interactions, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 49.4% and 60.9%, respectively. We also found the modified gear entangled 51.6% less southern flounder, which corresponded to a 32% reduction in total weight; the experimental sections entangled slightly larger individuals than the control sections. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. In addition, we found that 41% of the Atlantic sturgeon encountered were in warmer (26‒30°C) than colder water.

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