Limits...
Strategic assessment of fisheries independent monitoring programs in the gulf of Mexico.

Suprenand PM, Drexler M, Jones DL, Ainsworth CH - PLoS ONE (2015)

Bottom Line: These indices are compared against values in Ecospace, and against previously published single-species stock assessments.We also evaluate the full suite of information derived from FIM within an ecosystem context, considering whether functional roles are over- or under-sampled, and whether sampling effort is proportional to the value of fish stocks.Results reveal that model derived fishery indices closely matched published indices for the majority of the functional groups, economic and ecological evaluation suggests that several piscivorous functional groups are under-sampled include forage base species that are likely to indirectly support fisheries for piscivores, and sampling efforts are not proportional to the value of some fish stocks.

View Article: PubMed Central - PubMed

Affiliation: University of South Florida-College of Marine Science, 140 7th Ave S, St. Petersburg, Florida, 33701, United States of America; Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, Florida, 34236, United States of America.

ABSTRACT
This study evaluates information produced from 14 fisheries independent monitoring programs (FIM) in the Gulf of Mexico. We consider the uniqueness of information from each program and its usefulness in estimating fisheries management indices. Biomass values of 35 functional groups are extracted from an operating model (Ecospace) with a method that replicates the patterns of historic FIM samplings. Observation error is added to these data in order to create a set of pseudo data that replicate the type and quality of information obtained from FIM programs. The pseudo data were put into a separate fishery assessment model (Pella-Tomlinson) to determine management indices of each functional group (maximum sustainable yield (MSY), biomass at MSY, and fishing mortality at MSY). These indices are compared against values in Ecospace, and against previously published single-species stock assessments. We also evaluate the full suite of information derived from FIM within an ecosystem context, considering whether functional roles are over- or under-sampled, and whether sampling effort is proportional to the value of fish stocks. Results reveal that model derived fishery indices closely matched published indices for the majority of the functional groups, economic and ecological evaluation suggests that several piscivorous functional groups are under-sampled include forage base species that are likely to indirectly support fisheries for piscivores, and sampling efforts are not proportional to the value of some fish stocks. Following ecological modelling we performed statistical analyses on historic FIM catch data to identify optimal species-specific sampling months and gear-types that can be used to refine future FIM sampling efforts.

No MeSH data available.


Related in: MedlinePlus

Accuracy of assessment model versus exponential Keystoneness by functional group.This figure illustrates the discrepancy (coefficient of variation) of Maximum Sustainable Yield (MSY) estimated between the (assessment) Pella-Tomlinson model and (operating) Ecospace model based on 2000 to 2008 data (red squares and regression line) and 2009 to 2012 data (blue diamonds and regression line). Keystoneness values were calculated by the Ecospace model. In general, ecologically important functional groups (towards the right of the figure) should be assessed by FIM programs with greater rigor and accuracy than other functional groups, providing a negative slope overall. That is not the case. Regression line slopes were significantly different from zero (t-test: 2000 to 2008 P-value = 0.05, 2009 to 2012 P-value = 0.01; values log-transformed), but not one another.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4383601&req=5

pone.0120929.g004: Accuracy of assessment model versus exponential Keystoneness by functional group.This figure illustrates the discrepancy (coefficient of variation) of Maximum Sustainable Yield (MSY) estimated between the (assessment) Pella-Tomlinson model and (operating) Ecospace model based on 2000 to 2008 data (red squares and regression line) and 2009 to 2012 data (blue diamonds and regression line). Keystoneness values were calculated by the Ecospace model. In general, ecologically important functional groups (towards the right of the figure) should be assessed by FIM programs with greater rigor and accuracy than other functional groups, providing a negative slope overall. That is not the case. Regression line slopes were significantly different from zero (t-test: 2000 to 2008 P-value = 0.05, 2009 to 2012 P-value = 0.01; values log-transformed), but not one another.

Mentions: Fig 2 reveals the discrepancy (coefficient of variation) of MSY estimated between the assessment and operating models based on 2000 to 2008 data and 2009 to 2012 data versus Ecospace catch values (tonnes km-2 year-1), which includes discards/bycatch. The years from 2009 to 2012 illustrated differences in FIM data for reasons discussed below, and therefore Figs 2, 3 and 4 were divided into results of the years before and after 2009. One might expect a priori that exploited species with high coefficients of variance towards the top in Fig 2 should be assessed by FIM programs with greater rigor than exploited species with a low coefficient of variance towards the bottom of the figure. Therefore, we expect to see a negative slope where accuracy of the stock assessment improves for species with large total catch. In general, that is the case, specifically for the functional groups of Mullet, Pin Fish, Scaled Sardine, and Silver Perch. Exploited functional groups with the least amount of accuracy are Grouper, Jacks, Mackerel, Pigfish and Pompano. With some important exceptions, the sampling efforts from 2009 to 2012 were less effective in producing accurate management index estimates than years’ previous, as demonstrated in the regression line’s more positive slope when compared to the 2000 to 2008 regression line. Both regression line slopes were significantly different from zero (t-test; 2000 to 2008 P-value = 0.02, 2009 to 2012 P-value = 0.05), and from one another (t-test; P = 0.01). These exceptions indicate that programmatic or technical changes to FIM since 2009 in the SEAMAP program have reduced accuracy for assessing high biomass fish populations in the GOM.


Strategic assessment of fisheries independent monitoring programs in the gulf of Mexico.

Suprenand PM, Drexler M, Jones DL, Ainsworth CH - PLoS ONE (2015)

Accuracy of assessment model versus exponential Keystoneness by functional group.This figure illustrates the discrepancy (coefficient of variation) of Maximum Sustainable Yield (MSY) estimated between the (assessment) Pella-Tomlinson model and (operating) Ecospace model based on 2000 to 2008 data (red squares and regression line) and 2009 to 2012 data (blue diamonds and regression line). Keystoneness values were calculated by the Ecospace model. In general, ecologically important functional groups (towards the right of the figure) should be assessed by FIM programs with greater rigor and accuracy than other functional groups, providing a negative slope overall. That is not the case. Regression line slopes were significantly different from zero (t-test: 2000 to 2008 P-value = 0.05, 2009 to 2012 P-value = 0.01; values log-transformed), but not one another.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383601&req=5

pone.0120929.g004: Accuracy of assessment model versus exponential Keystoneness by functional group.This figure illustrates the discrepancy (coefficient of variation) of Maximum Sustainable Yield (MSY) estimated between the (assessment) Pella-Tomlinson model and (operating) Ecospace model based on 2000 to 2008 data (red squares and regression line) and 2009 to 2012 data (blue diamonds and regression line). Keystoneness values were calculated by the Ecospace model. In general, ecologically important functional groups (towards the right of the figure) should be assessed by FIM programs with greater rigor and accuracy than other functional groups, providing a negative slope overall. That is not the case. Regression line slopes were significantly different from zero (t-test: 2000 to 2008 P-value = 0.05, 2009 to 2012 P-value = 0.01; values log-transformed), but not one another.
Mentions: Fig 2 reveals the discrepancy (coefficient of variation) of MSY estimated between the assessment and operating models based on 2000 to 2008 data and 2009 to 2012 data versus Ecospace catch values (tonnes km-2 year-1), which includes discards/bycatch. The years from 2009 to 2012 illustrated differences in FIM data for reasons discussed below, and therefore Figs 2, 3 and 4 were divided into results of the years before and after 2009. One might expect a priori that exploited species with high coefficients of variance towards the top in Fig 2 should be assessed by FIM programs with greater rigor than exploited species with a low coefficient of variance towards the bottom of the figure. Therefore, we expect to see a negative slope where accuracy of the stock assessment improves for species with large total catch. In general, that is the case, specifically for the functional groups of Mullet, Pin Fish, Scaled Sardine, and Silver Perch. Exploited functional groups with the least amount of accuracy are Grouper, Jacks, Mackerel, Pigfish and Pompano. With some important exceptions, the sampling efforts from 2009 to 2012 were less effective in producing accurate management index estimates than years’ previous, as demonstrated in the regression line’s more positive slope when compared to the 2000 to 2008 regression line. Both regression line slopes were significantly different from zero (t-test; 2000 to 2008 P-value = 0.02, 2009 to 2012 P-value = 0.05), and from one another (t-test; P = 0.01). These exceptions indicate that programmatic or technical changes to FIM since 2009 in the SEAMAP program have reduced accuracy for assessing high biomass fish populations in the GOM.

Bottom Line: These indices are compared against values in Ecospace, and against previously published single-species stock assessments.We also evaluate the full suite of information derived from FIM within an ecosystem context, considering whether functional roles are over- or under-sampled, and whether sampling effort is proportional to the value of fish stocks.Results reveal that model derived fishery indices closely matched published indices for the majority of the functional groups, economic and ecological evaluation suggests that several piscivorous functional groups are under-sampled include forage base species that are likely to indirectly support fisheries for piscivores, and sampling efforts are not proportional to the value of some fish stocks.

View Article: PubMed Central - PubMed

Affiliation: University of South Florida-College of Marine Science, 140 7th Ave S, St. Petersburg, Florida, 33701, United States of America; Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, Florida, 34236, United States of America.

ABSTRACT
This study evaluates information produced from 14 fisheries independent monitoring programs (FIM) in the Gulf of Mexico. We consider the uniqueness of information from each program and its usefulness in estimating fisheries management indices. Biomass values of 35 functional groups are extracted from an operating model (Ecospace) with a method that replicates the patterns of historic FIM samplings. Observation error is added to these data in order to create a set of pseudo data that replicate the type and quality of information obtained from FIM programs. The pseudo data were put into a separate fishery assessment model (Pella-Tomlinson) to determine management indices of each functional group (maximum sustainable yield (MSY), biomass at MSY, and fishing mortality at MSY). These indices are compared against values in Ecospace, and against previously published single-species stock assessments. We also evaluate the full suite of information derived from FIM within an ecosystem context, considering whether functional roles are over- or under-sampled, and whether sampling effort is proportional to the value of fish stocks. Results reveal that model derived fishery indices closely matched published indices for the majority of the functional groups, economic and ecological evaluation suggests that several piscivorous functional groups are under-sampled include forage base species that are likely to indirectly support fisheries for piscivores, and sampling efforts are not proportional to the value of some fish stocks. Following ecological modelling we performed statistical analyses on historic FIM catch data to identify optimal species-specific sampling months and gear-types that can be used to refine future FIM sampling efforts.

No MeSH data available.


Related in: MedlinePlus