scholarly journals Diet composition and foraging ecology of U.S. Pacific Coast groundfishes with applications for fisheries management

2016 ◽  
Vol 100 (4) ◽  
pp. 375-393 ◽  
Author(s):  
Joseph J. Bizzarro ◽  
Mary M. Yoklavich ◽  
W. Waldo Wakefield
Keyword(s):  
Fisheries Management ◽  
Diet Composition ◽  
Pacific Coast ◽  
Foraging Ecology

scholarly journals Dinámica espacio-temporal del esfuerzo en una pesquería de buceo artesanal multiespecífica y sus efectos en la variabilidad de las capturas: Implicaciones para el manejo sostenible

2014 ◽  
Vol 62 (4) ◽  
pp. 1565 ◽  
Author(s):  
Helven Naranjo Madrigal ◽  
Silvia Salas Márquez
Keyword(s):  
Fisheries Management ◽  
Pacific Coast ◽  
Temporal Dynamics ◽  
Fishing Effort ◽  
The North ◽  
Fishing Strategies ◽  
Personal Consumption ◽  
Spatial And Temporal Dynamics ◽  
The North Pacific

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), and the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 70.5%, while free diving, with a sample of 69.5%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (<em>Panulirus gracilis</em>), octopus (<em>Octopus</em> sp.) and parrotfish (<em>Scarus perrico</em> and <em>S. ghobban</em>). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.

Evaluating the impacts of metabarcoding primer selection on DNA characterization of diet in an aerial insectivore, the Purple Martin

The Auk ◽  
2021 ◽  
Author(s):  
Anna M Forsman ◽  
Brandon D Hoenig ◽  
Stephanie A Gaspar ◽  
Jason D Fischer ◽  
Joe Siegrist ◽  
...  
Keyword(s):  
Diet Composition ◽  
Foraging Ecology ◽  
Molecular Technique ◽  
Insectivorous Birds ◽  
Alpha And Beta Diversity ◽  
Primer Selection ◽  
Aerial Insectivore ◽  
Dna Metabarcoding ◽  
The Usa ◽  
Primer Sets

Abstract DNA metabarcoding is a molecular technique frequently used to characterize diet composition of insectivorous birds. However, results are sensitive to methodological decisions made during sample processing, with primer selection being one of the most critical. The most frequently used DNA metabarcoding primer set for avian insectivores is ZBJ. However, recent studies have found that ZBJ produces significant biases in prey classification that likely influence our understanding of foraging ecology. A new primer set, ANML, has shown promise for characterizing insectivorous bat diets with fewer taxonomic biases than ZBJ, but ANML has not yet been used to study insectivorous birds. Here, we evaluate the ANML primer set for use in metabarcoding of avian insectivore diets through comparison with the more commonly used ZBJ primer set. Fecal samples were collected from both adult and nestling Purple Martins (Progne subis subis) at 2 sites in the USA and 1 site in Canada to maximize variation in diet composition and to determine if primer selection impacts our understanding of diet variation among sites. In total, we detected 71 arthropod prey species, 39 families, and 10 orders. Of these, 40 species were uniquely detected by ANML, whereas only 11 were uniquely detected by ZBJ. We were able to classify 54.8% of exact sequence variants from ANML libraries to species compared to 33.3% from ZBJ libraries. We found that ANML outperformed ZBJ for PCR efficacy, taxonomic coverage, and specificity of classification, but that using both primer sets together produced the most comprehensive characterizations of diet composition. Significant variation in both alpha- and beta-diversity between sites was found using each primer set separately and in combination. To our knowledge, this is the first published metabarcoding study using ANML primers to describe avian diet, and also the first to directly compare results returned by ANML and ZBJ primer sets.

Diet composition and foraging ecology of Asian elephants in Shangyong, Xishuangbanna, China

2006 ◽  
Vol 26 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Jin Chen ◽  
Xiaobao Deng ◽  
Ling Zhang ◽  
Zhilin Bai
Keyword(s):  
Diet Composition ◽  
Foraging Ecology ◽  
Asian Elephants

scholarly journals Foraging ecology of the amphibious mudskipper Periophthalmus chrysospilos (Gobiiformes: Gobiidae)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12582
Author(s):  
Quang Minh Dinh ◽  
Ton Huu Duc Nguyen ◽  
Tran Thi Huyen Lam ◽  
Tien Thi Kieu Nguyen ◽  
Giang Van Tran ◽  
...  
Keyword(s):  
Digestive Tract ◽  
Intertidal Zone ◽  
Diet Composition ◽  
Foraging Ecology ◽  
Feeding Strategy ◽  
Mekong Delta ◽  
Food Composition ◽  
Food Items ◽  
Marine Connectivity ◽  
Dietary Component

The food composition and feeding ecology of fishes living in the intertidal zone play an essential role in understanding the energetic connectivity between terrestrial and aquatic systems. Periophthalmus chrysospilos is an amphibious fish species occurring in the intertidal zone, but data on its diet and foraging ecology is still poorly known. This study on Ps. chrysospilos was carried out from April 2020 to March 2021 at four sites within the Mekong Delta estuary to define the influence of spatio-temporal factors on the diet of this species. The diet composition and relative gut lengths (RGLs) of Ps. chrysospilos were analysed in relation to four parameters—sex, size, site, and season. A total of 1,031 individuals were collected, and their digestive tract lengths were used to calculate the RGL. The digestive tracts of only 546 individuals were with food items (approximately 1:1 of empty vs full digestive tract) and were subsequently used for further analyses. The ranges in total length and weight in both adult and juvenile individuals were 3.4–10.6 cm and 0.38–14.13 g, respectively. The RGL values varied with season, fish size and site, but was always lower than 1, indicating a predominantly carnivorous diet. The variability of food items found within the digestive tracts demonstrated its adaptability in pursuing prey items within the limits of the littoral zone, and its importance as a conduit of terrestrial-marine connectivity. This species is characterised as an opportunistic mesopredator feeding primarily on Acetes spp., Uca spp., Dolichoderus sp., and rarely on Polychaeta and Actinopterygii. Other items found within the digestive tract are Mollusca, and detritus. The diet composition of Ps. chrysospilos did not vary with season and size, but changed with sex and site parameters. Uca spp. contributed to the sexual variation in dietary component, whereas Mollusca, Uca spp., Dolichoderus sp. and detritus, were drivers for spatial variation in the dietary component. The research provides fundamental information on diet composition and feeding strategy, as well as contributes towards knowledge on foraging ecology and resource use by intertidal animal communities.

scholarly journals Inuit Knowledge of beluga whale (Delphinapterus leucas) foraging ecology in Nunavik (Arctic Quebec), Canada

2016 ◽  
Vol 94 (10) ◽  
pp. 713-726 ◽  
Author(s):  
K. Breton-Honeyman ◽  
M.O. Hammill ◽  
C.M. Furgal ◽  
B. Hickie
Keyword(s):  
Diet Composition ◽  
Foraging Ecology ◽  
Arctic Region ◽  
Beluga Whale ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Productive Area ◽  
Inuit Knowledge ◽  
Beluga Whale Delphinapterus Leucas

The beluga whale (Delphinapterus leucas (Pallas, 1776)) is expected to be influenced by changes in the environment. In Nunavik, the Arctic region of Quebec, Nunavimmiut (Inuit of Nunavik) have depended on beluga for centuries, developing an extensive understanding of the species and its ecology. Forty semidirective interviews were conducted with Inuit hunters and Elders from four Nunavik communities, who had a range of 28–47 years of beluga hunting experience. Interviews followed an ethnocartographic format and were analyzed using a mixed methods approach. Hunters most commonly reported prey species from the sculpin (Cottidae), cod (Gadidae), salmon (Salmonidae), and crustacean families; regional variations in prey and in foraging habitat were found. Hunters identified significant changes in body condition (i.e., blubber thickness), which were associated with observations about the seasonality of feeding. The timing of fat accumulation in the late fall and winter coupled with the understanding that Hudson Bay is not known as a productive area suggest alternate hypotheses to feeding for the seasonal movements exhibited by these whales. Inuit Knowledge of beluga foraging ecology presented here provides information on diet composition and seasonality of energy intake of the beluga and can be an important component of monitoring diet composition for this species into the future. An Inuttitut version of the abstract is available ( Appendix A ).

The diet of Pacific gulls (Larus pacificus) breeding at Seal Island in northern Bass Strait

2014 ◽  
Vol 62 (3) ◽  
pp. 216 ◽  
Author(s):  
Tamara N. Leitch ◽  
Peter Dann ◽  
John P. Y. Arnould
Keyword(s):  
Marine Environment ◽  
Diet Composition ◽  
Prey Species ◽  
Foraging Ecology ◽  
Wide Distribution ◽  
Analysis Of Similarity ◽  
Numerical Abundance ◽  
Important Predator ◽  
The Common ◽  
Diving Petrel

The endemic Pacific gull (Larus pacificus) is Australia’s largest larid, and though little is currently known of its foraging ecology, its size and wide distribution suggest that it may play an important role within the marine environment. In the present study, regurgitate pellets collected from Seal Island in northern Bass Strait were used to compare intra- and interannual trends in diet composition. The main taxa identified in pellets were the common diving-petrel (Pelecanoides urinatrix), leatherjacket species (Family Monacanthidae), short-tailed shearwater (Puffinus tenuirostris) and mirror bush (Coprosma repens). Analysis of similarity (ANOSIM) identified no significant differences in numerical abundance of the dominant prey species between years, suggesting that the prey base in this region is temporally consistent or that the gulls consume low enough numbers to be unaffected by fluctuation in prey populations. Diving-petrels were consumed in consistently high numbers, suggesting the gulls may be an important predator of this species, or that the gulls are particularly skilled at foraging for them.

Foraging ecology of the agile wallaby (Macropus agilis) in the wet - dry tropics

2002 ◽  
Vol 29 (4) ◽  
pp. 347 ◽  
Author(s):  
Simon C. Stirrat
Keyword(s):  
Seasonal Changes ◽  
Diet Composition ◽  
Foraging Ecology ◽  
Foraging Strategy ◽  
In Vitro Digestibility ◽  
Wet Season ◽  
Dry Tropics ◽  
Seasonal Environment ◽  
Herbage Quality

Seasonal changes in diet composition and diet preferences of the agile wallaby (Macropus agilis) were investigated in East Point Reserve, Darwin. The wallabies were almost exclusively grazers in the wet season when the nitrogen content and in vitro digestibility of herbage were high. Evidence suggests that wallabies rarely browsed in the wet season. The diet consisted mainly of non-leguminous forbs, reflecting the abundance of these plants in the study site, but the wallabies showed higher preference for grasses and legumes. In the dry season herbage quality was poor and the wallabies grazed on available green grasses and forbs but also broadened their diet considerably to include a range of alternative foods, including browse, leaf litter, fruits, flowers and roots. A flexible foraging strategy allows agile wallabies to exploit a range of resources in this highly seasonal environment where periods of food shortage may be long and their duration unpredictable.

scholarly journals The Diet of the Magnificent Frigatebird During Chick Rearing

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 569-576 ◽  
Author(s):  
Itzia Calixto-Albarrán ◽  
José-Luis Osorno
Keyword(s):  
Diet Composition ◽  
Pacific Coast ◽  
Prey Species ◽  
Prey Size ◽  
The Pacific ◽  
Prey Composition ◽  
Males And Females ◽  
Changes Over Time ◽  
Over Time ◽  
Opportunistic Feeding

Abstract We describe the diet of the Magnificent Frigatebird Fregata magnificens at Isla Isabel off the Pacific coast of Mexico based on 158 regurgitates (555 prey items) from males, females, chicks, and juveniles. The diet included 50 species of fishes (21 identified to genus only), 1 species of squid, and 2 species of crustaceans. Diplectum pacificum and Anchoa lucida were the most frequent species of fish in the frigatebird's diet. No differences in prey composition or prey size were found between males and females, but females disgorged 62% more food. This difference mirrors the bigger size (15% larger than males) and larger contribution of females to chick feeding. Flying juveniles consumed prey in different proportions than the adults and disgorged marginally more food. Juveniles may obtain food in different patches than adults and complement this source with maternal feedings, or they may be more likely to regurgitate. Diet composition of males, females, and flying juveniles changed during the 4-month period of this study, but the mass of regurgitates did not change as the breeding season progressed, suggesting that availability of prey species changes over time. Most of the diet of this population probably comes from opportunistic feeding on fisheries, because the variety of fishes disgorged is remarkably similar to the published list of fishes discarded by prawn-fishing boats in the area. If our assumption is true, kleptoparasitism and direct fishing are only marginally represented in the diet of this population.

Sign in / Sign up

Export Citation Format

Share Document