Influence of food and predation on the depth distribution of juvenile spot (Leiostomus xanthurus) in tidal nurseries

1995 ◽  
Vol 52 (5) ◽  
pp. 971-982 ◽  
Author(s):  
Robert J. Miltner ◽  
Steve W. Ross ◽  
Martin H. Posey
Keyword(s):  
North Carolina ◽  
Benthic Invertebrates ◽  
Laboratory Experiments ◽  
Depth Distribution ◽  
Leiostomus Xanthurus ◽  
Tidal Creeks ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Influence Of Food ◽  
Young Of The Year

Relative abundances of young-of-the-year (YOY) spot (Leiostomus xanthurus) sampled by trawling in two tidal creeks on Masonboro Island, North Carolina, were highest in the shallow creek margins. Abundances of benthic invertebrates sampled by cores in one of the study creeks, were also maximal at the creek margin. Polychaetes associated with the creek margin composed the largest fraction of spot diets, indicating spot located in the creek margins were in the area of highest food availability. Spot predators sampled by trawling and seining were uncommon and were primarily juvenile (75–200 mm total length) southern flounder (Paralichthys lethostigma), hake (Urophycis spp.), and bluefish (Pomotomus saltatrix). Large YOY spot experienced a size refuge from predation, as only small YOY spot were found in predator stomachs. In laboratory experiments testing the effects of the presence of a predator, food, or both food and predators on the depth distribution of YOY spot, food had a stronger effect on spot distributions than predators The results of field observations and laboratory experiments suggest food has the strongest effect on spot distribution in the field, and that food is relatively more important than refuge from predation to the nursery function of shallow estuarine habitats.

Winter winds and river discharge determine juvenile southern flounder (Paralichthys lethostigma) recruitment and distribution in North Carolina estuaries

2010 ◽  
Vol 64 (1-2) ◽  
pp. 15-25 ◽  
Author(s):  
J. Christopher Taylor ◽  
John M. Miller ◽  
Leonard J. Pietrafesa ◽  
David A. Dickey ◽  
Steve W. Ross
Keyword(s):  
North Carolina ◽  
River Discharge ◽  
Paralichthys Lethostigma ◽  
Southern Flounder

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.

A Modified Freeze-Core Technique to Quantify the Depth Distribution of Fauna in Stony Streambeds

1983 ◽  
Vol 40 (5) ◽  
pp. 637-643 ◽  
Author(s):  
C. W. Pugsley ◽  
H. B. N. Hynes
Keyword(s):  
Vertical Distribution ◽  
Liquid Nitrogen ◽  
Benthic Invertebrates ◽  
Depth Distribution ◽  
Sampling Methods ◽  
Freezing Front ◽  
Southern Ontario ◽  
Freeze Core ◽  
Order Of Magnitude ◽  
The Vertical Distribution

A freeze-coring device using liquid nitrogen is described, which enables one person to take a columnar core, extending from the surface to at least 50 cm below a stony streambed. An experiment to validate the technique showed that animals did not flee from the advance of the freezing-front. Using frozen streambed cores, the vertical distribution of benthic invertebrates of two streams in southern Ontario was investigated. In contrast to previous estimates,~70% of the fauna was found in the top 10 cm of the streambed, and invertebrate densities were often lower by an order of magnitude. These differences are attributed to problems of quantifying previous sampling methods.

Collection Efficiency of Seine and Rotenone Samples from Tidal Creeks, Cape Fear River, North Carolina

Estuaries ◽  
1980 ◽  
Vol 3 (2) ◽  
pp. 98 ◽  
Author(s):  
Michael P. Weinstein ◽  
Robert W. Davis
Keyword(s):  
North Carolina ◽  
Collection Efficiency ◽  
Tidal Creeks ◽  
Cape Fear River ◽  
Cape Fear

Planktivory by alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) on microcrustacean zooplankton and dreissenid (Bivalvia: Dreissenidae) veligers in southern Lake Ontario

1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman
Keyword(s):  
Laboratory Experiments ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Field Observations ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Consumption Rates ◽  
South Shore ◽  
Young Of The Year ◽  
Veliger Larvae

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.

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