Fish Reproductive Biology (eBook)

Implications for Assessment and Management

Tore Jakobsen, Michael J. Fogarty, Bernard A. Megrey, Erlend Moksness (Herausgeber)

eBook Download: EPUB

2016 | 2. Auflage
John Wiley & Sons (Verlag)
9781118752708 (ISBN)

Infos

Fish recruitment is a key process for maintaining sustainable fish populations. In the marine environment, fish recruitment is carried out in many different ways, all of which have different life history strategies. The objective of this book is to argue for greater linkages between basic and applied research on fisheries recruitment, and assessment and management of exploited fish stocks.

Following an introductory chapter, this second edition of Fish Reproductive Biology is organized into 3 main sections:

• Biology, Population Dynamics and Recruitment
• Information Critical to Successful Assessment and Management
• Incorporation of Reproductive Biology and Recruitment Considerations into Management Advice and Strategies

The authors collectively bring a wide range of diverse experience in areas of reproductive biology, fisheries oceanography, stock assessment, and management.

Fully updated throughout, the book will be of great interest to a wide audience. It is useful as a textbook in graduate and undergraduate courses in fisheries biology, fisheries science, and fisheries resource management and will provide vital information for fish biologists, fisheries scientists and managers.

Tore Jakobsen is Senior Scientist at the Institute of Marine Research, Bergen, Norway  

Michael Fogarty is Senior Scientists at the Northeast Fisheries Center, National Marine Fisheries Service, Woods Hole, Massachusetts, USA

Erlend Moksness is Research Director, Institute of Marine Research, Flodevigen Marine Research Station, Arendal, Norway.
Erlend has also edited the following books for Blackwell/Wiley-Blackwell: Culture of Cold-Water Marine Fish (2004), Integrated Coastal Zone Management (2009), Global Challenges in Coastal Zone Management (NYP 2013).

Inhalt

Contributors vii

Preface ix

Acronyms x

Introduction 1
Tore Jakobsen, Michael J. Fogarty, Bernard A. Megrey and Erlend Moksness

Part I Biology, Population Dynamics, and Recruitment

Chapter 1 Recruitment in Marine Fish Populations 11
Michael J. Fogarty and Loretta O'Brien

Chapter 2 Reproductive Dynamics 50
Dimitri A. Pavlov and Natal'ya G. Emel'yanova

Chapter 3 Recruitment Variability 98
Edward D. Houde

Chapter 4 Effects of Fishing on the Population 188
Marie-Jo¨elle Rochet and Lise Marty

Part II Information Critical to Successful Assessment and Management

Chapter 5 Egg, Larval, and Juvenile Surveys 229
Nancy C.H. Lo, Paul E. Smith, and Motomitsu Takahashi

Chapter 6 Stock Identification 252
Gavin A. Begg and Steven X. Cadrin

Chapter 7 Stock Assessment Models and Predictions of Catch and Biomass 279
John G. Pope

Chapter 8 Applied Fisheries Reproductive Biology: Contribution of Individual Reproductive Potential to Recruitment and Fisheries Management 321
Olav S. Kjesbu

Part III Incorporation of Reproductive Biology and Recruitment Considerations into Management Advice and Strategies

Chapter 9 Current Paradigms and Forms of Advice 369
Kevern L. Cochrane

Chapter 10 Management: New Approaches to Old Problems 395
Carl M. O'Brien

Chapter 11 Implementing Information on Stock Reproductive Potential in Fisheries Management: The Motivation, Challenges and Opportunities 438
C. Tara Marshall

Species Index 465

Subject Index 468

A colour plate section falls between pages 292 and 293

Textauszug

Introduction

Tore Jakobsen, Michael J. Fogarty, Bernard A. Megrey and Erlend Moksness

As long as humans have exploited marine fish resources, fluctuations in availability and yields have been experienced. Nearly a century ago Hjort (1914, 1926) linked variation in yield to variability in recruitment, and today scientists still identify recruitment as a major driving force in stock fluctuations. This is reflected in the research focus on reproductive dynamics and recruitment over the past 30 years (see: http://www2.ncsu.edu/elhs/elhspubs.html) and in recent strategic plans by the International Council for the Exploration of the Sea (ICES) (Anon. 2001). Most international research programmes focusing on reproductive biology and recruitment of marine fishes do so to improve the understanding of the underlying processes controlling survival and growth during the early life stages. Few are aimed primarily at directly linking these processes to the assessment and management of harvested stocks, although progress in this area is evident. As exploited fish stocks decline, the demand for information on recruitment dynamics and for better prediction of recruitment typically increases. Furthermore, there is an increasing awareness of the importance of understanding these mechanisms for fisheries management.

The realisation that recruitment processes are of fundamental importance to the prosecution and management of fisheries has resulted in concerted efforts to monitor recruitment and to understand the factors controlling variability of marine fish populations. These efforts provide an unparalleled opportunity to study processes regulating fish populations and to understand and predict the impacts of harvesting on living marine resources. An extremely valuable compendium of estimates of adult biomass and recruitment has been assembled for exploited marine resources throughout the world's oceans (http://www.mscs.dal.ca/~myers/welcome.html), offering opportunities to examine patterns of recruitment variability, compensatory dynamics, and the current status of these stocks. The economic importance of fishes and their societal and cultural relevance provide powerful incentives for large-scale, sustained studies of their dynamics. Few other taxonomic groups – terrestrial or aquatic – offer such rich databases for examination of these processes as those available for fishes.

Scope and organisation of the book

The overall goal of this book is to provide a picture of the present use of information on fish reproductive biology in assessment and management and its potential for improving management of these resources. We have divided this book into three main parts. The first part sets the stage by focusing on recruitment processes, reproductive biology and the effects of fishing on exploited marine fishes. Here, we describe the critical role of recruitment in replenishing an exploited population, the importance of fundamental reproductive dynamics in this process, and how natural and anthropogenic forcing factors affect recruitment and sustainability. The second part explores the fundamental elements for any evaluation of fish population dynamics. These encompass issues related to identifying populations and stock units, estimation methods for obtaining abundance and demographic information at different life history stages, and the data requirements for more refined estimates of reproductive output and dynamics for inclusion in assessment and management. The final part describes both the current approach to management and ways in which a detailed understanding of reproductive processes can inform new approaches to management. Contributions to each of these parts are described in greater detail below. We also provide below references to key texts for further reading which complement the material presented in the individual chapters.

Biology, population dynamics and recruitment

Consideration of the form of the relationship between the reproductive output of the population and the resulting recruitment lies at the very heart of any understanding of how a fish population will respond to sustained perturbations such as fishing (Chambers & Trippel 1997). This issue has been a focus of fisheries research for the past half century. Any such representation depends on an understanding of the life-cycle dynamics of the population from the production of viable eggs, through the gauntlet of processes that affect the probability of survival, to the age or size at recruitment. If we are to predict the likely effects of fishing on an exploited population we require conceptual and analytical models of this process. In Chapter 1, these considerations are used to introduce the principal themes recurring throughout this book, including how a refined understanding of reproductive dynamics influences our perception of the status of the population, the relationship between the adult population and recruitment, and the choice of effective management strategies. The earliest recruitment models were cast in terms of total egg production. However, the general lack of time series of information on fecundity at the time necessitated the use of a proxy for this quantity – usually the total adult biomass of the population (Beverton & Holt 1957). The focus of these early efforts therefore was on the compensatory mechanisms that shape the relationship between spawning stock biomass and recruitment. There is now accumulating evidence that the spawning stock biomass alone is not always an adequate measure of the spawning potential of a fish stock. Maternal factors such as fecundity and egg quality are known to be affected by growth, condition, body size and spawning class. Furthermore, sex ratios of many populations change with increasing fishing pressure in combination with selective harvesting practices. Collectively, these considerations argue for a return to the origins of recruitment theory with its recognition of the importance of the actual reproductive output of the population. Translated into a management setting, we see that ignoring the effective reproductive output of a population and status of the adult population in some cases can lead to an overly optimistic view of the condition of the population with attendant risks to sustainability.

The importance of gaining a detailed understanding of reproductive processes of fish in the context of recruitment studies has long been appreciated (Potts & Wootton 1984). Chapter 2 provides essential background on the reproductive biology of fishes with considerations spanning cellular development of primordial germ cells, individual fecundity, reproductive strategies, ontogenetic development and factors affecting the quality of reproductive products. An understanding of the reproductive processes of fish at the cellular level is ultimately necessary to correctly determine and interpret the potential reproductive output of a population. An understanding of reproductive strategies and mating systems is no less important for some species. Semelparous life histories, in which adults spawn once and die, are notable among species such as capelin and Pacific salmon, while iteroparity involving multiple reproductive opportunities throughout the lifespan is common in most other fish taxa. Most fishes maintain separate sexes throughout the lifespan, but various forms of sequential hermaphroditism are also known among a number of important exploited species. Discrete seasonal patterns of spawning are common in temperate and boreal systems and are often linked to seasonal primary and secondary production cycles. In contrast, many tropical and subtropical species spawn throughout the year.

Factors underlying the characteristically large variation in recruitment of fishes, broadly classified into trophodynamic and physical/environmental components, are described in Chapter 3. The striking prevalence of highly variable recruitment patterns in marine fishes and the recognised underlying importance of stabilising mechanisms has been called the stock–recruitment paradox (Rothschild 1986). Trophodynamic considerations such as prey availability during the pre-recruit stages and the risk of predation on the pre-recruits strongly influence survival. Physical processes such as turbulence can directly affect the probability of prey capture, while other physical factors such as temperature affect activity levels and metabolic requirements. The role of transport, retention and loss has been linked to variation in survival during the early life stages of fish. Survival depends on successful transport to and/or retention within favourable habitats. Different early life stages exhibit different vulnerabilities to these environmentally driven events. Although recruitment variability obviously is linked to processes in the local environment, there is evidence that these processes are driven by large-scale environmental variations. Thus, major climate and oceanic events have been shown to have effects on fish populations over a wide area. Fish populations respond to biotic and abiotic environmental forcing on both short (high-frequency) and long (low-frequency) time scales. The high levels of interannual variation in recruitment characteristically observed in fish stocks reflect high frequency forcing, while long-term regime shifts in environmental factors are followed by changes in overall recruitment levels. High- and low-frequency changes in recruitment hold very different implications for the development and evaluation of management strategies. In the former case, stochasticity in recruitment should be taken into account in making short-term tactical management decisions. In the latter, adjustments of...

Produkt-Details

• Erscheint lt. Verlag: 22.1.2016
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Zoologie
• Themenwelt: Technik
• Themenwelt: Weitere Fachgebiete ► Land- / Forstwirtschaft / Fischerei
• Schlagworte: Animal Reproduction • Aquaculture, Fisheries & Fish Science • Aquakultur, Fischereiwesen u. Fischforschung • assessment of fisheries • Biowissenschaften • Fisch u. Fischfang • Fish & Fisheries • fisheries biology • Fisheries Oceanography • fisheries recruitment • Fisheries Science • Life Sciences • Management • population dynamics • Recruitment • Reproductive Biology • Stock assessment • Zoologie / Fortpflanzung
• ISBN-13: 9781118752708 / 9781118752708