Growth and condition in relation to the lack of recovery of northern cod
| Autor: | Mariano Koen-Alonso, M. Joanne Morgan, Rick M. Rideout, Alejandro D. Buren, Dawn Maddock Parsons |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Ecology 010604 marine biology & hydrobiology Protein metabolism Zoology Aquatic animal Lipid metabolism Aquatic Science Biology Oceanography 010603 evolutionary biology 01 natural sciences Population density Population Decrease Aquatic organisms chemistry.chemical_compound chemistry Growth rate Ecology Evolution Behavior and Systematics Body condition |
| Zdroj: | ICES Journal of Marine Science. 75:631-641 |
| ISSN: | 1095-9289 1054-3139 |
| Popis: | Growth and condition in fishes have been taken as indicating levels of energy available for survival and reproduction, major components of a population’s productivity. After a rapid collapse in population size, northern (NAFO Division 2J3KL) cod (Gadus morhua) remained at a very low level of abundance for 20 years. We investigated the potential for poor growth and condition to have played a role in the collapse and lack of recovery of northern cod. Juveniles and adult males and females all showed similar patterns. Perceptions about the importance of growth and condition to population status depended on the metrics and area examined. When the northern cod population was declining, the northern areas of the population clearly had reduced growth and condition, while these metrics improved in the south. Results were equivocal as to the potential role of growth and condition in the continued low abundance of northern cod and, to some extent, depended on the nature of the metric being examined. Indices of condition, which included lipid storage in the form of liver weight, were generally lower in the north while the stock remained at a low level. Metrics associated with longer-term protein storage returned to precollapse levels quickly following the period of collapse. An index of food availability was more closely related to growth and condition than was temperature. These results point to the need both for studies of growth and condition in a population to have a comprehensive time-series of data covering the entire range of the population and the need for a better understanding of the causes and implications of changes in different metrics of condition. |
| Databáze: | OpenAIRE |
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