scholarly journals Are Cape Cormorants Phalacrocorax capensis losing the competition? Dietary overlap with commercial fisheries

Ostrich ◽  
2021 ◽  
pp. 1-15
Author(s):  
OB Masiko ◽  
PG Ryan ◽  
CD van der Lingen ◽  
L Upfold ◽  
S Somhlaba ◽  
...  
Keyword(s):  
Commercial Fisheries ◽  
Dietary Overlap

Predicting changes in distribution of a large coastal shark in the face of the strengthening East Australian Current

2020 ◽  
Vol 642 ◽  
pp. 163-177 ◽  
Author(s):  
Y Niella ◽  
AF Smoothey ◽  
V Peddemors ◽  
R Harcourt
Keyword(s):  
Austral Summer ◽  
Conservation Strategies ◽  
Limiting Factor ◽  
Commercial Fisheries ◽  
East Australian Current ◽  
Spatial And Temporal Patterns ◽  
Marine Animals ◽  
Factors Affecting ◽  
Southeastern Australia ◽  
The Face

In the face of accelerating climate change, conservation strategies will need to consider how marine animals deal with forecast environmental change as well as ongoing threats. We used 10 yr (2009-2018) of data from commercial fisheries and a bather protection program along the coast of New South Wales (NSW), southeastern Australia, to investigate (1) spatial and temporal patterns of occurrence in bull sharks and (2) environmental factors affecting bull shark occurrence along the coast of NSW. Predicted future distribution for this species was modelled for the forecast strengthening East Australian Current. Bull sharks were mostly harvested in small to larger estuaries, with average depth and rainfall responsible for contrasting patterns for each of the fisheries. There was an increase in the occurrence of bull sharks over the last decade, particularly among coastal setline fisheries, associated with seasonal availability of thermal gradients >22°C and both westward and southward coastal currents stronger than 0.15 and 0.60 m s-1, respectively, during the austral summer. Our model predicts a 3 mo increase in the availability of favourable water temperatures along the entire coast of NSW for bull sharks by 2030. This coastline provides a uniquely favourable topography for range expansion in the face of a southerly shift of warmer waters, and habitat is unlikely to be a limiting factor for bull sharks in the future. Such a southerly shift in distribution has implications for the management of bull sharks both in commercial fisheries and for mitigation of shark-human interactions.

Status of Commercial Fisheries in the Kingdom of Bahrain

2013 ◽  
Vol 26 (1 (special Issue)) ◽  
pp. 220-238 ◽  
Author(s):  
Thamer S. Ali ◽  
Asma A. Abahussain
Keyword(s):  
Commercial Fisheries

Dietary Overlap But Spatial Gap between Sympatric Japanese Serow (Capricornis crispus) and Sika Deer (Cervus nippon) on Eastern Shikoku, Japan

Mammal Study ◽  
2019 ◽  
Vol 44 (4) ◽  
pp. 261
Author(s):  
Asuka Yamashiro ◽  
Yoshinori Kaneshiro ◽  
Yoichi Kawaguchi ◽  
Tadashi Yamashiro
Keyword(s):  
Sika Deer ◽  
Cervus Nippon ◽  
Dietary Overlap ◽  
Japanese Serow

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

Who's onboard? A predictive analysis of cooperative formation in commercial fisheries

2021 ◽  
Vol 279 ◽  
pp. 111715
Author(s):  
Michael De Alessi ◽  
Michael C. Melnychuk ◽  
Edward Wort ◽  
Ray Hilborn
Keyword(s):  
Predictive Analysis ◽  
Commercial Fisheries

Book Reviews

2014 ◽  
Vol 52 (2) ◽  
pp. 565-567
Keyword(s):  
Oil And Gas ◽  
Arctic Region ◽  
Economic Benefits ◽  
Infrastructure Investment ◽  
Commercial Fisheries ◽  
International Studies ◽  
Oil And Gas Development ◽  
Resource Exploration ◽  
Benefits And Costs

Michael A. Goldstein, Professor of Finance, Babson College reviews “Arctic Economics in the 21st Century: The Benefits and Costs of Cold” by Heather A. Conley. The Econlit abstract of this book begins: “Explores the economic benefits of an increasingly open Arctic region and the costs of exploring the riches of the American Arctic. Discusses Arctic frontiers; U.S. Arctic oil and gas development; Arctic mineral resource exploration; Arctic destination and trans-shipping; Arctic commercial fisheries; Arctic ecotourism; and Arctic infrastructure investment. Conley is Director and Senior Fellow of the Europe Program at the Center for Strategic and International Studies.”

Fish Attraction with Pulsed Low-Frequency Sound

1968 ◽  
Vol 25 (7) ◽  
pp. 1441-1452 ◽  
Author(s):  
Joseph D. Richard
Keyword(s):  
Acoustic Stimulus ◽  
Low Frequency ◽  
Reef Fishes ◽  
Test Site ◽  
Acoustic Signals ◽  
Commercial Fisheries ◽  
Test Results ◽  
Potential Applications ◽  
Predatory Fishes ◽  
Underwater Television

A series of tests were conducted to determine the effectiveness of pulsed low-frequency acoustic signals for attracting fishes. The acoustic signals were contrived to simulate the hydrodynamically generated disturbances normally associated with active predation. Underwater television was used to observe fish arrivals during both control and test periods. Demersal predatory fishes were successfully attracted although they habituated rapidly to the acoustic stimulus. Members of the families Serranidae, Lutjanidae, and Pomadasyidae were particularly well represented among the fishes attracted. Sharks were also attracted in considerable numbers. Herbivorous reef fishes, although common around the test site, were not attracted. Possible relationships between the test results and the hearing capabilities of fishes are discussed. It is concluded that acoustic attraction techniques have potential applications in certain existing commercial fisheries.

scholarly journals Resource partitioning between kit foxes (Vulpes macrotis) and coyotes (Canis latrans): a comparison of historical and contemporary dietary overlap

2018 ◽  
Vol 96 (5) ◽  
pp. 497-504 ◽  
Author(s):  
P.A. Byerly ◽  
R.C. Lonsinger ◽  
E.M. Gese ◽  
A.J. Kozlowski ◽  
L.P. Waits
Keyword(s):  
Great Basin ◽  
Native Species ◽  
Dietary Diversity ◽  
Canis Latrans ◽  
Population Level ◽  
Relative Importance ◽  
Dietary Overlap ◽  
Kit Fox ◽  
Prey Diversity ◽  
Vulpes Macrotis

Range expansions by generalists can alter communities and introduce competitive pressures on native species. In the Great Basin Desert, USA, coyotes (Canis latrans Say, 1823) have colonized and are now sympatric with native kit foxes (Vulpes macrotis Merriam, 1888). Since both species have similar diets, dietary partitioning may facilitate coexistence. We analyzed coyote and kit fox diets, then compared our results to an earlier study. Because populations are dynamic, we expected that decreases in prey or increases in predator abundance could alter dietary patterns. We found no significant changes in population-level prey diversity for kit foxes or coyotes, but found high levels of dietary overlap between species. We did detect a significant decrease in the relative importance of leporids (family Leporidae) in the diets of both canids, but they remained important for coyotes. The relative importance of small mammals was greater for kit foxes than coyotes, but their importance had not changed significantly over time. We detected significant declines in prey diversity per sample (scat-level dietary diversity) for both canids, suggesting that during a foraging event, individuals may encounter less diverse prey now than historically. These findings suggested that kit foxes and coyotes were not limited by prey, despite high dietary overlap.

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