Suam Kim

Little is known about how marine fishes respond to the reduced pH condition caused by the increased CO₂ in the atmosphere. We investigated the effects of CO₂ concentration on the growth of olive flounder (Paralichthys olivaceus) larvae. Newly hatched larvae were reared in three different concentrations of CO₂ (574, 988 and 1297 μatm CO₂) in temperature-controlled water tanks until metamorphosis (4 weeks). Body lengths, weights, and the concentration of some chemical elements in larval tissue were measured at the completion of each experiment, and experiment was repeated three times in May, June, and July 2011. Results indicated that body length and weight of flounder larvae were significantly increased with increasing CO₂ concentration (P < 0.05). Daily growth rates of flounder larvae were higher (0.391 mm) from the high CO₂ concentration (1297 μatm) than those (0.361 mm and 0.360 mm) from the lower ones (988 and 574 μatm).The measurement on some chemical elements (Ca, Fe, Cu, Zn and Sr) in fish tissue also revealed the increasing tendency of element concentration with increasing CO₂ in seawater, although statistical significance cannot be tested due to the single measurement. It suggests that there are enrichment processes of these cations in larval tissue in the low pH condition.

An integrated fisheries risk assessment method has been developed recently for assessing fisheries at the ecosystem level. It makes use of objectives, indicators, and reference points to assess the states of species, fisheries, and ecosystems. This pragmatic method for assessing fisheries at the ecosystem level involves a two-tier system to accommodate the quantity and quality of the available data. A number of indicators were selected for both tiers to assess systems for three management objectives, namely, sustainability, biodiversity, and habitat quality. Nested risk indices were developed to assess ecosystem status at the management unit level. The complexity and usefulness of the method were demonstrated by applying it to the “Tongyeong marine ranch” in Korea. It is hoped that assessment and management at this level will prevent significant and potentially irreversible changes in marine ecosystems caused by fishing, and aid efforts to recover depleted fish stocks in Korean marine ecosystems. Introduction The basic and inter-related problems of current world fisheries include the threat of over-exploitation of resources, over-capitalization or over-expansion of fishing fleets, and the negative consequences of fisheries on the survival of marine life and associated habitats. The diverse, dynamic, and complex nature of fishery management problems necessitates the development of a process that accounts for more human interactions, as well as improved definition of biological indicators that can be applied. Resource managers, researchers, user groups, and other interested parties must be involved in the process to minimize conflict and maximize commitment to sustainable management (Zhang and Marasco 2003).

Showing how big-picture patterns can help overcome the failures of conventional management, this book is ideal for students, researchers and professionals involved with marine fisheries. It explores not only the current practice of the 'ecosystem approach' to fisheries management but also its critical importance to even larger perspectives. The first section gives a valuable overview of how more and more of the complexity of real-world systems is being recognized and involved in the management of fisheries around the world. The second section then demonstrates how important aspects of real-world systems, involving population dynamics, evolution and behavior, remain to be taken into account completely. This section also shows how we must change the way we think about our involvement in, and the complexity of, marine ecosystems. The final chapters consider how, with the use of carefully chosen macroecological patterns, we can take important steps towards more holistic management of marine fisheries.