scholarly journals Effects of fish stocking and fishing pressure on fish community structures in French lakes

2021 ◽  
Author(s):  
Léa Daupagne ◽  
Marlène Rolan‐Meynard ◽  
Maxime Logez ◽  
Christine Argillier
Keyword(s):  
Fish Community ◽  
Fishing Pressure ◽  
Community Structures ◽  
Fish Stocking

scholarly journals COMMUNITY STRUCTURE AND TROPHIC STATUS OF REEF FISH IN NATUNA WATERS

2020 ◽  
Vol 26 (2) ◽  
pp. 69
Author(s):  
Isa Nagib Edrus ◽  
Pratiwi Lestari
Keyword(s):  
Reef Fish ◽  
Fish Community ◽  
Field Research ◽  
Reef Fishes ◽  
Species Number ◽  
Community Structures ◽  
Underwater Visual Census ◽  
The Mean ◽  
Coral Health ◽  
Density And Biomass

A field research on reef fish-community structures in Natuna waters was carried out in November 2015. This research aimed to obtain the trophic composition of reef fishes and its correlation to diversity, density, and biomass. Underwater visual census on several transect areas was used to collect data. Results show that the identified reef fishes were about 100 species of target-reef fish belonging to 18 families and 23 species of indicator-reef fish of the Chaetodontidae family. The mean species number of target reef fish and indicator reef fish were 42 and 7 species, respectively. The  mean density of the target reef fish and indicator reef fish were 0.4 and 0.05 individual per m2, respectively. The mean of the reef fish relative stock was 0.6 ton/ha. The composition of the herbivores mostly found in the resilient coral reefs r was 46.45 % and the omnivores and planktivores as marketable targeted fishes were 18.64 % and 14.28 %, respectively. The most predominant or major families were from herbivorous, carnivorous, planktivorous, and corallivorous fishes, including Scaridae (i.e. Scarus spp), Lutjanidae (i.e. Lutjanus spp.), Caesionidae (i,e. Caesio cuning and Pterocaesio caerulaurea), and Chaetodontidae (i.e. Chaetodon baronessa and Chaetodon octofasciatus). The results suggested that the community structures were quite prospectively implemented for fisheries; however, it may not be promising for coral resilience. Furthermore, the coral health status was at moderate level in regard to the high numbers of corallivorous butterflyfishes.

scholarly journals Tracking the changes of a fish community following a megascale reclamation and ensuing mitigation measures

2013 ◽  
Vol 70 (6) ◽  
pp. 1206-1219 ◽  
Author(s):  
Yin-Ki Tam ◽  
I-Hsun Ni ◽  
Cynthia Yau ◽  
Man-Yee Yan ◽  
Wai-Shan Chan ◽  
...  
Keyword(s):  
Community Structure ◽  
Community Health ◽  
Fish Community ◽  
Time Lag ◽  
Mitigation Measures ◽  
Fish Density ◽  
Dynamic Factor ◽  
Large Species ◽  
Fishing Pressure ◽  
Fast Growing

Abstract Tam, Y-K., Ni, I-H., Yau, C., Yan, M-Y., Chan, W-S., Chan, S-M., Lu, H-J. 2013. Tracking the changes of a fish community following a megascale reclamation and ensuing mitigation measures. – ICES Journal of Marine Science, 70: 1206–1219. A fish community in Hong Kong that had experienced megascale reclamation in Chek Lap Kok International Airport, and the ensuing marine protected areas (MPAs) establishment was tracked for 12 years. Significant shifts in community structure, typified by 17 species, were revealed by multivariate analyses and community metrics. Dynamic factor analysis disclosed two underlying common trends among them and their significant correlations with changes in water quality, area of seabed disturbance, and area of MPAs. A time-lag for detectable community changes was also revealed. During reclamation, the fish density was low and community health was poor. Large species disappeared leaving a community dominated by small, fast-growing and young-to-mature species. After completion of reclamation, some large and medium species returned, but soon after the establishment of MPAs, medium-sized, fast-growing and young-to-mature species thrived on reduction of fishing pressure, and filled the guilds rapidly. Therefore, even though fish density and community health were improved, the original community structure was not restored. This study provides a good reference for impacts of reclamation at the community level and the possible outcomes of reducing fishing pressure in a depleted fish community.

Recovery of zooplankton assemblages in mountain lakes from the effects of introduced sport fish

2001 ◽  
Vol 58 (9) ◽  
pp. 1822-1830 ◽  
Author(s):  
David B Donald ◽  
Rolf D Vinebrooke ◽  
R Stewart Anderson ◽  
Jim Syrgiannis ◽  
Mark D Graham
Keyword(s):  
Fish Community ◽  
Mountain Lakes ◽  
Zooplankton Species ◽  
Introduced Fish ◽  
Fish Stocking ◽  
Fish Removal ◽  
Fishless Lakes ◽  
Chi Squared ◽  
Community Complexity ◽  
Sport Fish

Impacts of introduced fish on zooplankton assemblages of lakes may persist for decades following fish removal. We tested this hypothesis by comparing zooplankton assemblages from four categories of lakes located in western Canadian mountain parks including lakes without and with fish that differed in their fish community complexity and fish-stocking history. Zooplankton species richness was greatest in lakes with a complex community of fish and least in pristine fishless lakes. Canonical correspondence analysis showed that taxonomic shifts in zooplankton assemblages could be attributed to differences in fish-stocking history between the study lakes. In fishless lakes, larger copepods (Eucyclops agilis, Diaptomus leptopus), cladocerans (Diaphanosoma, large Daphnia), and chaoborids were abundant, whereas in the presence of fish, small crustaceans were more common and chaoborids were relatively rare. Once introduced trout were absent from lakes, recovery trajectories for zooplankton showed a general taxonomic shift towards assemblages characteristic of fishless lakes that had never been fish stocked. Based on separation between previously stocked fishless lakes and naturally fishless mountain lakes in ordination space (chi-squared distance), taxonomic recovery by zooplankton assemblages from the influence of introduced salmonids may require an average of 19 years.

scholarly journals Development of the EcoQO for the North Sea fish community

2010 ◽  
Vol 68 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Simon P. R. Greenstreet ◽  
Stuart I. Rogers ◽  
Jake C. Rice ◽  
Gerjan J. Piet ◽  
Emma J. Guirey ◽  
...  
Keyword(s):  
North Sea ◽  
Fish Community ◽  
Environmental Influence ◽  
Fish Stock ◽  
Fishing Pressure ◽  
Stock Management ◽  
The North ◽  
A Value ◽  
The North Sea ◽  
Sea Fish

Abstract Greenstreet, S. P. R., Rogers, S. I., Rice, J. C., Piet, G. J., Guirey, E. J., Fraser, H. M., and Fryer, R. J. 2011. Development of the EcoQO for the North Sea fish community. – ICES Journal of Marine Science, 68: 1–11. Development of the Ecological Quality Objective (EcoQO) for the North Sea demersal fish community is described. Size-based metrics were identified as the most effective indicators of the state of the community, but such metrics are also sensitive to environmental influence. Redefining the large fish indicator (LFI) produced a metric more sensitive to fishing-induced change and therefore more useful to managers. Fish stocks were thought to be exploited at a sustainable rate in the early 1980s, so in a process echoing the precautionary approach to fish stock management, this was considered the reference period for the LFI, suggesting a value of 0.3 as the appropriate EcoQO. The LFI declined from around 0.3 in 1983 to 0.05 in 2001, followed by a recovery to 0.22 in 2008. However, analyses of the longer-term groundfish survey data suggest that, even were fishing pressure to be reduced to early 20th century levels, the LFI would be unlikely to rise much above a value of 0.3. The response of the LFI to variation in fishing pressure suggested a more complex relationship than anticipated, underscoring the need for operational theoretical size-resolved multispecies fish community models to support management towards broader ecosystem objectives.

Assessing the sensitivity and specificity of fish community indicators to management action

2012 ◽  
Vol 69 (6) ◽  
pp. 1065-1079 ◽  
Author(s):  
Jennifer E. Houle ◽  
Keith D. Farnsworth ◽  
Axel G. Rossberg ◽  
David G. Reid
Keyword(s):  
Sensitivity And Specificity ◽  
Fish Community ◽  
Ecosystem Approach ◽  
Large Species ◽  
Fishing Pressure ◽  
Fishing Mortality ◽  
Size Selection ◽  
Community Model ◽  
Community Monitoring ◽  
Specific Biomass

We assessed ten trophodynamic indicators of ecosystem status for their sensitivity and specificity to fishing management using a size-resolved multispecies fish community model. The responses of indicators to fishing depended on effort and the size selectivity (sigmoid or Gaussian) of fishing mortality. The highest specificity against sigmoid (trawl-like) size selection was seen from inverse fishing pressure and the large fish indicator, but for Gaussian size selection, the large species indicator was most specific. Biomass, mean trophic level of the community and of the catch, and fishing in balance had the lowest specificity against both size selectivities. Length-based indicators weighted by biomass, rather than abundance, were more sensitive and specific to fishing pressure. Most indicators showed a greater response to sigmoid than Gaussian size selection. Indicators were generally more sensitive at low levels of effort because of nonlinear sensitivity in trophic cascades to fishing mortality. No single indicator emerged as superior in all respects, so given available data, multiple complementary indicators are recommended for community monitoring in the ecosystem approach to fisheries management.

scholarly journals Comparing demersal fish assemblages between periods of contrasting climate and fishing pressure

2011 ◽  
Vol 68 (6) ◽  
pp. 1189-1198 ◽  
Author(s):  
Remment ter Hofstede ◽  
Adriaan D. Rijnsdorp
Keyword(s):  
Climate Change ◽  
North Sea ◽  
Fish Community ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Warm Period ◽  
Cold Period ◽  
Past Century ◽  
Fishing Pressure ◽  
Southern North Sea

Abstract ter Hofstede, R., and Rijnsdorp, A. D. 2011. Comparing demersal fish assemblages between periods of contrasting climate and fishing pressure. – ICES Journal of Marine Science, 68: 1189–1198. Fish communities are dynamic and their structure is known to change over time. Traditionally, these changes were considered to be fisheries-induced, but recent analyses also suggest that global warming could affect the distribution, abundance, and assemblage composition of marine fish. However, disentangling the effects of fisheries and those resulting from climate change is difficult, because both potential drivers act simultaneously. In our study, we distinguished between the effects of fisheries and climate change on the fish assemblage of the southern North Sea by comparing survey catch data for that region during four unique periods throughout the past century, characterized by (i) low fishing pressure during a cold period (1902–1908), (ii) low fishing pressure during a warm period (1950–1956), (iii) high fishing pressure during a cold period (1978–1984), and (iv) high fishing pressure during a warm period (2002–2008). Our analysis indicates that the demersal fish community in the southern North Sea has changed in response to changes in both climate and fishing pressure. Our results suggest both a relatively higher richness of Lusitanian (warm-favouring) species compared with boreal (cool-favouring) species, and a lower mean body size of the fish community during times of warming, independent of fishing pressure.

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