Correlations of Fish Catch and Environmental Factors in the Gulf of Maine

1977 ◽  
Vol 34 (1) ◽  
pp. 19-30 ◽  
Author(s):  
W. H. Sutcliffe Jr. ◽  
K. Drinkwater ◽  
B. S. Muir

In an investigation of catches of 17 commercial marine species of fish and shellfish from the Gulf of Maine, 10 showed statistically significant correlations with sea temperatures at St. Andrews, N.B., or Boothbay Harbour, Maine. Most fish records contained at least 40 yr of data. Descriptive equations are produced for four species based first on the correlation between catch and sea temperature and second on the correlation between catch and sea temperature allowing for fishing effort. Inclusion of fishing effort, not surprisingly, improved the correlations for all of the species so examined. The equations permitted the "prediction" of later parts of the records from earlier parts.Considering the fish species collectively, the Gulf of Maine system from 1940 to 1959 appeared to be in equilibrium with little fluctuation in the total commercial biomass. We interpret the large fluctuations in individual species abundance as resulting from a combination of fishing pressure and to a significant degree oceanic climate as represented by sea temperature. The small fluctuations in the total biomass displays the species variation, with their differing climatic "preferences," as well as possible predator (including man)–prey relationships. Environmentally imposed patterns underlie at least 50% of the fluctuations in catch of many species and the understanding of these fluctuations is basic to effective management.

1987 ◽  
Vol 44 (9) ◽  
pp. 1568-1573 ◽  
Author(s):  
K. F. Drinkwater ◽  
R. A. Myers

Previous studies by Sutcliffe and co-workers using exploratory analysis found correlations between environmental variables and lagged annual catch for several Gulf of St. Lawrence and Gulf of Maine fish and shellfish stocks. The present study tests these relationships using recent data. For 6 of the 13 stocks investigated, correlations between the 9–14 yr of new catch data and that predicted from the environmental models remained high (r > 0.5) and of the same sign; however, individually none was statistically significant (p > 0.05) after accounting for the loss of degrees of freedom due to the high autocorrelation in the data. The hypothesis of an overall environmental effect on the landings was considered. It could not be substantiated as the correlation coefficient for 5 of the 13 stocks reversed sign using the new data, but changes in fishing effort are believed to mask detection of environmentally induced variability in the landings of many stocks. The utility of environmentally based predictions was also tested. Overall, the mean deviations of the predicted catch based on environmental regressions were similar to predictions based on the long-term means but were higher than predictions using lagged catch. Environmentally based predictions of landings for invertebrate stocks were generally more accurate than those for fish stocks.


2008 ◽  
Vol 65 (2) ◽  
pp. 242-254 ◽  
Author(s):  
Cynthia Yeung ◽  
Robert A. McConnaughey

Abstract Yeung, C., and McConnaughey, R. A. 2008. Using acoustic backscatter from a sidescan sonar to explain fish and invertebrate distributions: a case study in Bristol Bay, Alaska. – ICES Journal of Marine Science, 65: 242–254. Environmental variables that are ecologically relevant and easily measured over large areas are useful for modelling species distributions and habitats. Continuous acoustic, sonar-backscatter data convey information about physical properties of the seabed, and hence could be a valuable addition to that suite of variables. We tested the potential utility of acoustic backscatter for improving habitat models of marine species using data from a pilot sidescan-sonar survey. Raw digital-backscatter data were processed with QTC SIDEVIEW and CLAMS software. Resultant acoustic variables—Q-values (Q1, Q2, and Q3), representing the first three principal components of the data derived from image analysis of backscatter echoes, and a complexity metric (compx) measuring the variance of Q-values in a geographic area—were used in multiple linear regression to model individual species abundance from bottom-trawl survey data. Habitat models for flathead sole (Hippoglossoides elassodon), Pacific cod (Gadus macrocephalus), walleye pollock (Theragra chalcogramma), red king crab (Paralithodes camtschaticus), basket star (Gorgonocephalus eucnemis), and sponges (Porifera) included acoustic variables as significant predictors. For these six taxa, full models explained 67–86% of variability in abundance, with 9–54% of that total contributed by the acoustic predictors, suggesting that acoustic data could advance habitat research for some bottom-associated marine species.


Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Álvaro J. Benítez ◽  
Dina Ricardo-Caldera ◽  
María Atencia-Pineda ◽  
Jesús Ballesteros-Correa ◽  
Julio Chacón-Pacheco ◽  
...  

Abstract Bats are mammals of great ecological and medical importance, which have associations with different pathogenic microorganisms. DNA barcoding is a tool that can expedite species identification using short DNA sequences. In this study, we assess the DNA barcoding methodology in bats from the Colombian Northern region, specifically in the Córdoba department. Cytochrome oxidase subunit I (COI) gene sequences of nine bat species were typified, and their comparison with other Neotropic samples revealed that this marker is suitable for individual species identification, with ranges of intra-species variation from 0.1 to 0.9%. Bat species clusters are well supported and differentiated, showing average genetic distances ranging from 3% between Artibeus lituratus and Artibeus planirostris, up to 27% between Carollia castanea and Molossus molossus. C. castanea and Glossophaga soricina show geographical structuring in the Neotropic. The findings reported in this study confirm DNA barcoding usefulness for fast species identification of bats in the region.


Author(s):  
Huaijiang He ◽  
Chunyu Zhang ◽  
Fengguo Du ◽  
Xiuhai Zhao ◽  
Song Yang ◽  
...  

Understory plants are important components of forest ecosystem productivity and diversity. Compared to biomass models of overstory canopy trees, few are available for understory saplings and shrubs and therefore their roles in estimation of forest carbon pools are often ignored. In this study, we harvested 24 understory species including 4 saplings, 9 tree-like shrubs and 11 typical shrubs in coniferous and broadleaved mixed forest in northeastern China and developed the best fit allometric equations of above- and below-ground and total biomass by species-specific or multispecies using morphological measurements of basal diameter, height and crown area as independent variables. The result showed that single basal diameter, height or crown area had good explanatory power for both species-specific and multispecies (p<0.001). The best-fit models included only basal diameter in sapling and tree-like shrubs, and combinations of crown area, height, and basal diameter in typical shrubs. The logarithmic model was most desired among the 4 model forms of linear, quadratic, multiple linear and logarithmic, for species-specific and multispecies. The models we developed should help the estimation of forest ecosystem carbon stocks, especially for belowground component, and provide tools for quantification of individual species biomass of understory plants.


2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2020 ◽  
Vol 4 ◽  
Author(s):  
Lidia Garrido-Sanz ◽  
Miquel Àngel Senar ◽  
Josep Piñol

Amplicon metabarcoding is an established technique to analyse the taxonomic composition of communities of organisms using high-throughput DNA sequencing, but there are doubts about its ability to quantify the relative proportions of the species, as opposed to the species list. Here, we bypass the enrichment step and avoid the PCR-bias, by directly sequencing the extracted DNA using shotgun metagenomics. This approach is common practice in prokaryotes, but not in eukaryotes, because of the low number of sequenced genomes of eukaryotic species. We tested the metagenomics approach using insect species whose genome is already sequenced and assembled to an advanced degree. We shotgun-sequenced, at low-coverage, 18 species of insects in 22 single-species and 6 mixed-species libraries and mapped the reads against 110 reference genomes of insects. We used the single-species libraries to calibrate the process of assignation of reads to species and the libraries created from species mixtures to evaluate the ability of the method to quantify the relative species abundance. Our results showed that the shotgun metagenomic method is easily able to set apart closely-related insect species, like four species of Drosophila included in the artificial libraries. However, to avoid the counting of rare misclassified reads in samples, it was necessary to use a rather stringent detection limit of 0.001, so species with a lower relative abundance are ignored. We also identified that approximately half the raw reads were informative for taxonomic purposes. Finally, using the mixed-species libraries, we showed that it was feasible to quantify with confidence the relative abundance of individual species in the mixtures.


Ecology ◽  
2012 ◽  
Author(s):  
Herman A. Verhoef

At the beginning of the 20th century there was much debate about the “nature” of communities. The driving question was whether the community was a self-organized system of co-occurring species or simply a haphazard collection of populations with minimal functional integration. At that time, two extreme views dominated the discussion: one view considered a community as a superorganism, the member species of which were tightly bound together by interactions that contributed to repeatable patterns of species abundance in space and time. This concept led to the assumption that communities are fundamental entities, to be classified as the Linnaean taxonomy of species. Frederick E. Clements was one of the leading proponents of this approach, and his view became known as the organismic concept of communities. This assumes a common evolutionary history for the integrated species. The opposite view was the individualistic continuum concept, advocated by H. A. Gleason. His focus was on the traits of individual species that allow each to live within specific habitats or geographical ranges. In this view a community is an assemblage of populations of different species whose traits allow persisting in a prescribed area. The spatial boundaries are not sharp, and the species composition can change considerably. Consequently, it was discussed whether ecological communities were sufficiently coherent entities to be considered appropriate study objects. Later, consensus was reached: that properties of communities are of central interest in ecology, regardless of their integrity and coherence. From the 1950s and 1960s onward, the discussion was dominated by the deterministic outcome of local interactions between species and their environments and the building of this into models of communities. This approach, indicated as “traditional community ecology,” led to a morass of theoretical models, without being able to provide general principles about many-species communities. Early-21st-century approaches to bringing general patterns into community ecology concern (1) the metacommunity approach, (2) the functional trait approach, (3) evolutionary community ecology, and (4) the four fundamental processes. The metacommunity approach implicitly recognizes and studies the important role of spatiotemporal dynamics. In the functional trait approach, four themes are focused upon: traits, environmental gradients, the interaction milieu, and performance currencies. This functional, trait-focused approach should have a better prospect of understanding the effects of global changes. Evolutionary community ecology is an approach in which the combination of community ecology and evolutionary biology will lead to a better understanding of the complexity of communities and populations. The four fundamental processes are selection, drift, speciation, and dispersal. This approach concerns an organizational scheme for community ecology, based on these four processes to describe all existing specific models and frameworks, in order to make general statements about process–pattern connections.


2016 ◽  
Vol 113 (11) ◽  
pp. 2964-2969 ◽  
Author(s):  
Andrew D. Barton ◽  
Andrew J. Irwin ◽  
Zoe V. Finkel ◽  
Charles A. Stock

Anthropogenic climate change has shifted the biogeography and phenology of many terrestrial and marine species. Marine phytoplankton communities appear sensitive to climate change, yet understanding of how individual species may respond to anthropogenic climate change remains limited. Here, using historical environmental and phytoplankton observations, we characterize the realized ecological niches for 87 North Atlantic diatom and dinoflagellate taxa and project changes in species biogeography between mean historical (1951–2000) and future (2051–2100) ocean conditions. We find that the central positions of the core range of 74% of taxa shift poleward at a median rate of 12.9 km per decade (km⋅dec−1), and 90% of taxa shift eastward at a median rate of 42.7 km⋅dec−1. The poleward shift is faster than previously reported for marine taxa, and the predominance of longitudinal shifts is driven by dynamic changes in multiple environmental drivers, rather than a strictly poleward, temperature-driven redistribution of ocean habitats. A century of climate change significantly shuffles community composition by a basin-wide median value of 16%, compared with seasonal variations of 46%. The North Atlantic phytoplankton community appears poised for marked shift and shuffle, which may have broad effects on food webs and biogeochemical cycles.


2018 ◽  
Vol 75 (4) ◽  
pp. 1473-1482 ◽  
Author(s):  
Bai Li ◽  
Jie Cao ◽  
Lisha Guan ◽  
Mackenzie Mazur ◽  
Yong Chen ◽  
...  

AbstractEstimating spatial distribution of a species is traditionally achieved using global regression models with the assumption of spatial stationarity of relationships between species and environmental variables. However, species abundance and environmental variables are often spatially correlated and the strength of environmental effects may exhibit spatial non-stationarity on the species distribution. We applied local models, such as season-, sex-, and size-specific geographically weighted regression (GWR) models, on American lobster to explore non-stationary environmental effects on the presence and density of lobsters in the inshore Gulf of Maine (GOM). This species and its fishery have undergone a dramatic increase in abundance over the past two decades. Model results showed that the strength of the estimated relationships in the western GOM were different with the relationships in the eastern GOM during 2000–2014. Bottom water temperature had a more significant positive impact on the increase of lobsters in the eastern GOM, while the influence of temperature was less significant in the west and the more distinguishable drivers of distribution needed to be identified. The estimation of locally varied relationships can further improve regionally informed management plans. The modeling approach can be widely applied to many other species or study areas.


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