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Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments.

Yu W, Chen X, Yi Q, Chen Y, Zhang Y - PLoS ONE (2015)

Bottom Line: The AMM model was found to perform better than the GMM model.The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii.This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

View Article: PubMed Central - PubMed

Affiliation: College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China; Collaborative Innovation Center for Distant-water Fisheries, Shanghai, 201306, China.

ABSTRACT
We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

No MeSH data available.


Related in: MedlinePlus

Comparing the performance of arithmetic mean model (AMM) and geometric mean model (GMM).The histogram donates the frequency of fishing effort in each HSI stratum estimated from AMM-based and GMM-based models. The solid line donates the catch per unit effort (CPUE) in each HSI stratum estimated from AMM-based and GMM-based models.
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pone.0122997.g005: Comparing the performance of arithmetic mean model (AMM) and geometric mean model (GMM).The histogram donates the frequency of fishing effort in each HSI stratum estimated from AMM-based and GMM-based models. The solid line donates the catch per unit effort (CPUE) in each HSI stratum estimated from AMM-based and GMM-based models.

Mentions: We estimated the average CPUE and percentage of fishing effort within each HSI stratum during 1998 to 2009 and further compared the performances of the two models (AMM and GMM) (Fig 5). High percentages of fishing effort for each month were observed within the AMM-based HSI class range of 0.4–0.6 and 0.6–0.8 and tended to be much higher compared with those within the GMM-based HSI model. For example, the areas with the HSI values of 0.4–0.6 and 0.6–0.8 in July attracted 45.6% and 45.2% of the total fishing efforts, respectively, based on the AMM model. While the fishing sites with the HSI values of 0.4–0.6 and 0.6–0.8 attracted only 35.5% and 29.5% of the total fishing efforts, respectively, according to the GMM model. The fishing efforts were found to be distributed uniformly among the HSI classes for the GMM model. In addition, both models showed that the average CPUE strongly fluctuated, however, the CPUE tended to increase with the HSI values in each month except in September. Clearly, it was notable that the AMM-based model yielded few fishing efforts in the poor habitat with HSI<0.2, and the fishing effort percentages obviously increased with the HSI values, the suitable habitat with the HSI>0.6 accounted for the largest fishing efforts in each month. However, although the majority of fishing efforts occurred in high HSI values based on the GMM-based model, fishing efforts were distributed in poor habitat during July to November. This comparison suggested that the AMM model better captured the theory mentioned in the method section, we thus considered the AMM model to be more suitable than the GMM model.


Variability of Suitable Habitat of Western Winter-Spring Cohort for Neon Flying Squid in the Northwest Pacific under Anomalous Environments.

Yu W, Chen X, Yi Q, Chen Y, Zhang Y - PLoS ONE (2015)

Comparing the performance of arithmetic mean model (AMM) and geometric mean model (GMM).The histogram donates the frequency of fishing effort in each HSI stratum estimated from AMM-based and GMM-based models. The solid line donates the catch per unit effort (CPUE) in each HSI stratum estimated from AMM-based and GMM-based models.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414546&req=5

pone.0122997.g005: Comparing the performance of arithmetic mean model (AMM) and geometric mean model (GMM).The histogram donates the frequency of fishing effort in each HSI stratum estimated from AMM-based and GMM-based models. The solid line donates the catch per unit effort (CPUE) in each HSI stratum estimated from AMM-based and GMM-based models.
Mentions: We estimated the average CPUE and percentage of fishing effort within each HSI stratum during 1998 to 2009 and further compared the performances of the two models (AMM and GMM) (Fig 5). High percentages of fishing effort for each month were observed within the AMM-based HSI class range of 0.4–0.6 and 0.6–0.8 and tended to be much higher compared with those within the GMM-based HSI model. For example, the areas with the HSI values of 0.4–0.6 and 0.6–0.8 in July attracted 45.6% and 45.2% of the total fishing efforts, respectively, based on the AMM model. While the fishing sites with the HSI values of 0.4–0.6 and 0.6–0.8 attracted only 35.5% and 29.5% of the total fishing efforts, respectively, according to the GMM model. The fishing efforts were found to be distributed uniformly among the HSI classes for the GMM model. In addition, both models showed that the average CPUE strongly fluctuated, however, the CPUE tended to increase with the HSI values in each month except in September. Clearly, it was notable that the AMM-based model yielded few fishing efforts in the poor habitat with HSI<0.2, and the fishing effort percentages obviously increased with the HSI values, the suitable habitat with the HSI>0.6 accounted for the largest fishing efforts in each month. However, although the majority of fishing efforts occurred in high HSI values based on the GMM-based model, fishing efforts were distributed in poor habitat during July to November. This comparison suggested that the AMM model better captured the theory mentioned in the method section, we thus considered the AMM model to be more suitable than the GMM model.

Bottom Line: The AMM model was found to perform better than the GMM model.The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii.This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

View Article: PubMed Central - PubMed

Affiliation: College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China; Collaborative Innovation Center for Distant-water Fisheries, Shanghai, 201306, China.

ABSTRACT
We developed a habitat suitability index (HSI) model to evaluate the variability of suitable habitat for neon flying squid (Ommastrephes bartramii) under anomalous environments in the Northwest Pacific Ocean. Commercial fisheries data from the Chinese squid-jigging vessels on the traditional fishing ground bounded by 35°-45°N and 150°-175°E from July to November during 1998-2009 were used for analyses, as well as the environmental variables including sea surface temperature (SST), chlorophyll-a (Chl-a) concentration, sea surface height anomaly (SSHA) and sea surface salinity (SSS). Two empirical HSI models (arithmetic mean model, AMM; geometric mean model, GMM) were established according to the frequency distribution of fishing efforts. The AMM model was found to perform better than the GMM model. The AMM-based HSI model was further validated by the fishery and environmental data in 2010. The predicted HSI values in 1998 (high catch), 2008 (average catch) and 2009 (low catch) indicated that the squid habitat quality was strongly associated with the ENSO-induced variability in the oceanic conditions on the fishing ground. The La Niña events in 1998 tended to yield warm SST and favorable range of Chl-a concentration and SSHA, resulting in high-quality habitats for O. bartramii. While the fishing ground in the El Niño year of 2009 experienced anomalous cool waters and unfavorable range of Chl-a concentration and SSHA, leading to relatively low-quality squid habitats. Our findings suggest that the La Niña event in 1998 tended to result in more favorable habitats for O. bartramii in the Northwest Pacific with the gravity centers of fishing efforts falling within the defined suitable habitat and yielding high squid catch; whereas the El Niño event in 2009 yielded less favorable habitat areas with the fishing effort distribution mismatching the suitable habitat and a dramatic decline of the catch of O. bartramii. This study might provide some potentially valuable insights into exploring the relationship between the underlying squid habitat and the inter-annual environmental change.

No MeSH data available.


Related in: MedlinePlus