16 - The development of mariculture and its implications for biodiversity

Summary

Abstract

Mariculture has become an important source of seaweed, shellfish and fish, especially for human food, and production is likely to continue to expand well into the next century.

Mariculture has both direct and indirect impacts on biodiversity through the consumption of natural resources and the production of wastes. Natural resources such as land, water, seed and feed are required, consumption varying with intensity of production. Wastes, comprising uneaten food, faecal and urinary products, chemicals, pathogens and feral animals, are released into the environment, quantities also being largely dependent upon production methods.

Particular attention is drawn to threats to marine biodiversity posed by wetland destruction, use of chemotherapeutants and translocation of exotic plants and animals. Awareness of the impact of mariculture on biodiversity, however, is growing. Legislative, economic and market forces are beginning to persuade producers to reduce the impact through the adoption of a range of measures, including better site selection, husbandry, waste collection and treatment methods. Mariculture technology also offers the possibilities of reducing the impact on marine biodiversity caused by fishing and by entrapment of anthropogenic wastes from coastal conurbations.

Introduction

World population continues to increase faster than global food supply. While 99% of food comes from terrestrial agriculture (Pimentel & Giampietro, 1994), this disguises the fact that in many, especially developing, countries the bulk of animal protein comes from fish and other aquatic products.