The Development of Bycatch Reduction Technology in the Southeastern United States Shrimp Fishery

1999 ◽  
Vol 33 (2) ◽  
pp. 51-56 ◽  
Author(s):  
John Watson ◽  
Daniel Foster ◽  
Scoll Nichols ◽  
Arvlnd Shah ◽  
Elizabeth Scoll-oenlon ◽  
...  

Shrimp trawl bycatch is a significant source of fishery induced mortality for managed species including red snapper (Lutjanus campechanus Poey), Spanish mackerel (Scomberomorus maculatus MitcheU), and weakfish (Cynoscion regalis Baloch, Schneider) in the southeastern United States. These species have been overfished and are under both state and federal management plans which include regulations mandating reduction of shrimp trawl bycatch mortality. In 1990 the U.S. Congress passed amendments to the Magnuson Fishery Conservation and Management Act (16 U.S.C. 1854) which called for a research program that included the design and evaluation of approaches for reducing shrimp trawl bycatch mortality. A strategic planning initiative addressing finfish bycatch in the Gulf of Mexico and southeastern Atlantic shrimp fisheries was developed by the Gulf and South Atlantic Fisheries Foundation through funding and guidance provided by the National Marine Fisheries Service. A cooperative research plan was developed in 1992 which included the identification, development, and evaluation of gear options for reducing bycatch in the Gulf of Mexico and southeastern Atlantic shrimp fisheries. Between 1990 and 1996 one hundred and forty five bycatch reduction conceptual gear designs contributed by fishers, net shops, gear technicians, and biologists were evaluated. Sixteen of these designs were tested on cooperative commercial shrimp vessels by observers under the southeast regional cooperative bycatch program. Analyses of data from commercial vessel testing indicates that two bycatch reduction designs have potential to significantly reduce shrimp trawl bycatch for weakfish and Spanish mackerel in the southeastern Atlantic and two designs have the potential to significantly reduce red snapper bycatch in the Gulf of Mexico. The fisheye and the extended funnel bycatch reduction devices have been mandated for use in the southeastern Atlantic shrimp fishery and the fisheye and Jones/Davis bycatch reduction devices have been mandated for use in the Gulf of Mexico shrimp trawl fishery.

<em>Abstract.</em>—We examined the swimming performance and behavior of red snapper, <em>Lutjanus campechanus. </em>Our intention was to use this information toward developing a more efficient bycatch reduction device for use in the Gulf of Mexico shrimp trawl fishery. Using a Brett type swim tunnel, we found a significant effect of fish size and season on red snapper critical swimming speeds. For fish ranging between 6 and 17 cm standard length, critical swimming speeds ranged from about 35–70 cm/s, depending upon season. However, critical swimming speeds did not differ between day and night. This was an important observation since the majority of shrimp trawling in the Gulf occurs at night. We constructed and tested in the laboratory, a Vortex Generating Bycatch Reduction Device (VGBRD) that may prove useful in the shrimp trawl fishery. During behavioral tests during daylight, 79.2% of red snapper exited the VGBRD in an average of 4.1 min. However, during night-time tests, only 17.6% of red snapper exited the VGBRD in an average of 5.0 min. Behavioral tests revealed a strong negative phototactic response in dark adapted red snapper. We found that, during night-time tests when the VGBRD was illuminated with LED lights placed downstream of the exit, 96% of red snapper exited the device in 7.1 min. In color/ contrast choice experiments, red snapper unerringly associated with the dark colored (black or dark green) panel placed on the bottom of the experimental tank. In another set of experiments, we found that snapper displayed a strong optomotor response, i.e. the tendency to following and match speeds with a moving pattern. Illumination, color/contrast, and/or the optomotor response may improve bycatch reduction device performance.


2001 ◽  
Vol 28 (2) ◽  
pp. 213 ◽  
Author(s):  
KENITIRO SUGUIO

Meanwhile the highest relative sea-level is the present one in southeastern United States (Gulf of Mexico) or in Netherlands coast, most of the Brazilian coast exhibited Holocene sea-levels higher than the present in the past. The Brazilian curves, representing the relative sea-level changes during last 7.000 years, are outlined using sedimentological, biological and prehistorical past sea-level records. This paper shows that these relative sea-level records, during the Holocene, can be suitably used to demonstrate the influence of the worldwide known paleoclimatic events, like the “Hypsithermal Age” and “Neoglaciation” on the Brazilian coast.


Zootaxa ◽  
2002 ◽  
Vol 28 (1) ◽  
pp. 1 ◽  
Author(s):  
JOHN M. FOSTER ◽  
RICHARD W. HEARD

The genus Ameroculodes Bousfield and Chevrier, 1966 is emended to accommodate a new species of oedicerotid amphipod, Ameroculodes miltoni, common to estuarine habitats of the southeastern United States. In this region the new species has been confused with Ameroculodes (=Monocu- lodes) edwardsi (Holmes, 1905) and Deflexilodes (= Monoculodes) intermedius (Shoemaker, 1930), both of which are distinctly larger and endemic to the cold temperate waters of the Northwest Atlantic. Ameroculodes miltoni can be distinguished from A. edwardsi by (1) having the postero-ventral margins of epimeral plates 1-3 rounded, (2) a short, blunt rostrum, (3) uropod 2 with relatively few dorsal spines on the peduncle, (4) and a subovate telson. Deflexilodes intermedius, like A. miltoni, has rounded epimeral plates, but is readily distinguished by the well-developed, elongate dactyls on its 3 rd and 4 th pereopods. Ameroculodes miltoni occurs over a wide range of salinities (<1°/ °° to 35°/ °° ) and is most common in medium to fine sand or sand-silt substrata. It appears to be an important biotic component of northern Gulf of Mexico estuaries.


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