Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years
Nowadays, overexploitation and climate change are among the major threats to fish production all over the world. In this study, we focused our attention on the Adriatic Sea (AS), a shallow semi-enclosed sub-basin showing the highest exploitation level and warming trend over the last decades within t...
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| Format: | Article |
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MDPI AG
2023-06-01
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| Series: | Fishes |
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| Online Access: | https://www.mdpi.com/2410-3888/8/7/341 |
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| author | Federico Calì Federica Stranci Mario La Mesa Carlotta Mazzoldi Enrico Arneri Alberto Santojanni |
| author_facet | Federico Calì Federica Stranci Mario La Mesa Carlotta Mazzoldi Enrico Arneri Alberto Santojanni |
| author_sort | Federico Calì |
| collection | DOAJ |
| description | Nowadays, overexploitation and climate change are among the major threats to fish production all over the world. In this study, we focused our attention on the Adriatic Sea (AS), a shallow semi-enclosed sub-basin showing the highest exploitation level and warming trend over the last decades within the Mediterranean Sea. We investigated the life history traits and population dynamics of the cold-water species whiting (<i>Merlangius merlangus</i>, Gadidae) 30 years apart, which is one of the main commercial species in the Northern AS. The AS represents its southern limit of distribution, in accordance with the thermal preference of this cold-water species. Fish samples were collected monthly using a commercial bottom trawl within the periods 1990–1991 and 2020–2021. The historical comparison highlighted a recent reduction in large specimens (>25 cm total length, TL), which was not associated with trunked age structures, therefore indicating a decrease in growth performance over a period of 30 years (<i>L<sub>∞</sub></i><sub>90–91</sub> = 29.5 cm TL; <i>L<sub>∞</sub></i><sub>20–21</sub> = 22.8 cm TL). The current size at first sexual maturity was achieved within the first year of life, at around 16 cm TL for males and 17 cm TL for females. In the AS, whiting spawns in batches from December to March, showing a reproductive investment (gonadosomatic index) one order of magnitude higher in females than in males. Potential fecundity (F) ranged from 46,144 to 424,298, with it being heavily dependent on fish size. We hypothesize that the decreased growth performance might be related to a metabolic constraint, possibly related to the increased temperature and its consequences. Moreover, considering the detrimental effects of size reduction on reproductive potential, these findings suggest a potential endangerment situation for the long-term maintenance of whiting and cold-related species in the AS, which should be accounted for in setting management strategies. |
| first_indexed | 2024-03-11T01:05:31Z |
| format | Article |
| id | doaj.art-3756cde949b2454ca065d2e49dcf0dd5 |
| institution | Directory Open Access Journal |
| issn | 2410-3888 |
| language | English |
| last_indexed | 2024-03-11T01:05:31Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fishes |
| spelling | doaj.art-3756cde949b2454ca065d2e49dcf0dd52023-11-18T19:17:58ZengMDPI AGFishes2410-38882023-06-018734110.3390/fishes8070341Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 YearsFederico Calì0Federica Stranci1Mario La Mesa2Carlotta Mazzoldi3Enrico Arneri4Alberto Santojanni5Department of Biological, Geological, and Environmental Sciences (BiGeA), Alma Mater Studiorum—University of Bologna, 40126 Bologna, ItalyDepartment of Biology, University of Padova, 35121 Padova, ItalyNational Research Council—Institute of Polar Sciences (CNR-ISP), 40129 Bologna, ItalyDepartment of Biology, University of Padova, 35121 Padova, ItalyNational Research Council—Institute for Marine Biological Resources and Biotechnologies (CNR-IRBIM), 60125 Ancona, ItalyNational Research Council—Institute for Marine Biological Resources and Biotechnologies (CNR-IRBIM), 60125 Ancona, ItalyNowadays, overexploitation and climate change are among the major threats to fish production all over the world. In this study, we focused our attention on the Adriatic Sea (AS), a shallow semi-enclosed sub-basin showing the highest exploitation level and warming trend over the last decades within the Mediterranean Sea. We investigated the life history traits and population dynamics of the cold-water species whiting (<i>Merlangius merlangus</i>, Gadidae) 30 years apart, which is one of the main commercial species in the Northern AS. The AS represents its southern limit of distribution, in accordance with the thermal preference of this cold-water species. Fish samples were collected monthly using a commercial bottom trawl within the periods 1990–1991 and 2020–2021. The historical comparison highlighted a recent reduction in large specimens (>25 cm total length, TL), which was not associated with trunked age structures, therefore indicating a decrease in growth performance over a period of 30 years (<i>L<sub>∞</sub></i><sub>90–91</sub> = 29.5 cm TL; <i>L<sub>∞</sub></i><sub>20–21</sub> = 22.8 cm TL). The current size at first sexual maturity was achieved within the first year of life, at around 16 cm TL for males and 17 cm TL for females. In the AS, whiting spawns in batches from December to March, showing a reproductive investment (gonadosomatic index) one order of magnitude higher in females than in males. Potential fecundity (F) ranged from 46,144 to 424,298, with it being heavily dependent on fish size. We hypothesize that the decreased growth performance might be related to a metabolic constraint, possibly related to the increased temperature and its consequences. Moreover, considering the detrimental effects of size reduction on reproductive potential, these findings suggest a potential endangerment situation for the long-term maintenance of whiting and cold-related species in the AS, which should be accounted for in setting management strategies.https://www.mdpi.com/2410-3888/8/7/341Adriatic Seawhitingotolithgrowth modelscold-water speciesdemersal resources |
| spellingShingle | Federico Calì Federica Stranci Mario La Mesa Carlotta Mazzoldi Enrico Arneri Alberto Santojanni Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years Fishes Adriatic Sea whiting otolith growth models cold-water species demersal resources |
| title | Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years |
| title_full | Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years |
| title_fullStr | Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years |
| title_full_unstemmed | Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years |
| title_short | Whiting (<i>Merlangius merlangus</i>) Grows Slower and Smaller in the Adriatic Sea: New Insights from a Comparison of Two Populations with a Time Interval of 30 Years |
| title_sort | whiting i merlangius merlangus i grows slower and smaller in the adriatic sea new insights from a comparison of two populations with a time interval of 30 years |
| topic | Adriatic Sea whiting otolith growth models cold-water species demersal resources |
| url | https://www.mdpi.com/2410-3888/8/7/341 |
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