The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea
The decline in walleye pollock (<i>Gadus chalcogrammus</i>) stocks in Korean waters is a major concern for fishery conservation and management. However, the causes and mechanisms of this collapse remain unclear. This study investigated the complex dynamics influencing the abundance of wa...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-03-01
|
| Series: | Water |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4441/16/7/955 |
| _version_ | 1797211909038014464 |
|---|---|
| author | Hae Kun Jung Jong Won Park Jae Hyeong Yang Joo Myun Park In Seong Han Chung Il Lee |
| author_facet | Hae Kun Jung Jong Won Park Jae Hyeong Yang Joo Myun Park In Seong Han Chung Il Lee |
| author_sort | Hae Kun Jung |
| collection | DOAJ |
| description | The decline in walleye pollock (<i>Gadus chalcogrammus</i>) stocks in Korean waters is a major concern for fishery conservation and management. However, the causes and mechanisms of this collapse remain unclear. This study investigated the complex dynamics influencing the abundance of walleye pollocks in the East Sea of Korea over several decades, by analyzing data from long-term changes in biological factors including composition of length and sex, catch, and oceanographic condition. Prior to the mid-1980s, the catch ratio of juveniles was higher than that of adults, with a higher proportion of females in both juvenile and adult catches compared to males. Especially, high fishing pressure on female individuals can be an important factor contributing to declining reproduction. Consequently, after the mid-1980s, there was a sudden decline in juvenile pollock catches. In the late 1980s, there was a rapid increase in sea surface temperature (SST) in the spawning grounds, resulting in a decrease in both the duration of suitable temperature for spawning and the regional proportion for suitable spawning conditions. Consequently, the decline in pollock stocks after the late 1980s due to overfishing of pollock in the mid-1980s was further exacerbated by the effects of SST warming after the late 1980s. These findings highlight the impact of overfishing and environmental factors on pollock stocks and indicate the need for appropriate fishery management practices to ensure the sustainable use of fishery resources. |
| first_indexed | 2024-04-24T10:33:58Z |
| format | Article |
| id | doaj.art-e5cf9e08918440e29093686d1d1750f4 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-04-24T10:33:58Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-e5cf9e08918440e29093686d1d1750f42024-04-12T13:27:02ZengMDPI AGWater2073-44412024-03-0116795510.3390/w16070955The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East SeaHae Kun Jung0Jong Won Park1Jae Hyeong Yang2Joo Myun Park3In Seong Han4Chung Il Lee5East Sea Fisheries Research Institute, National Institute of Fisheries Science, Gangneung 25435, Republic of KoreaDepartment of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Republic of KoreaCoastal Water Fisheries Resources Research Division, National Institute of Fisheries Science, Busan 46083, Republic of KoreaDokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science & Technology, Uljin 36315, Republic of KoreaOcean Climate & Ecology Research Division, National Institute of Fisheries Science, Busan 46083, Republic of KoreaDepartment of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Republic of KoreaThe decline in walleye pollock (<i>Gadus chalcogrammus</i>) stocks in Korean waters is a major concern for fishery conservation and management. However, the causes and mechanisms of this collapse remain unclear. This study investigated the complex dynamics influencing the abundance of walleye pollocks in the East Sea of Korea over several decades, by analyzing data from long-term changes in biological factors including composition of length and sex, catch, and oceanographic condition. Prior to the mid-1980s, the catch ratio of juveniles was higher than that of adults, with a higher proportion of females in both juvenile and adult catches compared to males. Especially, high fishing pressure on female individuals can be an important factor contributing to declining reproduction. Consequently, after the mid-1980s, there was a sudden decline in juvenile pollock catches. In the late 1980s, there was a rapid increase in sea surface temperature (SST) in the spawning grounds, resulting in a decrease in both the duration of suitable temperature for spawning and the regional proportion for suitable spawning conditions. Consequently, the decline in pollock stocks after the late 1980s due to overfishing of pollock in the mid-1980s was further exacerbated by the effects of SST warming after the late 1980s. These findings highlight the impact of overfishing and environmental factors on pollock stocks and indicate the need for appropriate fishery management practices to ensure the sustainable use of fishery resources.https://www.mdpi.com/2073-4441/16/7/955East Seawalleye pollockfisheries managementoverfishingoceanographic condition |
| spellingShingle | Hae Kun Jung Jong Won Park Jae Hyeong Yang Joo Myun Park In Seong Han Chung Il Lee The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea Water East Sea walleye pollock fisheries management overfishing oceanographic condition |
| title | The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea |
| title_full | The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea |
| title_fullStr | The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea |
| title_full_unstemmed | The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea |
| title_short | The Long-Term Dynamics of Walleye Pollock Stocks in Relation to Oceanographic Changes in the East Sea |
| title_sort | long term dynamics of walleye pollock stocks in relation to oceanographic changes in the east sea |
| topic | East Sea walleye pollock fisheries management overfishing oceanographic condition |
| url | https://www.mdpi.com/2073-4441/16/7/955 |
| work_keys_str_mv | AT haekunjung thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT jongwonpark thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT jaehyeongyang thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT joomyunpark thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT inseonghan thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT chungillee thelongtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT haekunjung longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT jongwonpark longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT jaehyeongyang longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT joomyunpark longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT inseonghan longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea AT chungillee longtermdynamicsofwalleyepollockstocksinrelationtooceanographicchangesintheeastsea |