Quantifying no net loss of productivity of fish habitats

A net change equation is derived for assessing no net loss of productivity of fish habitat (NNL). NNL is the guiding principle of the Canadian policy for the management of fish habitat. The equation provides a middle ground between the extremes of no conservation and no development. Projects affecting fish habitat are accountable for the productive capacity in loss areas and the difference between current and future productivities in modified areas. The equation implies quantitative conservation targets overall and loss-offsetting equivalencies in modified habitat areas. Generalization of the net change equation to heterogeneous habitats is illustrated with a development in a coastal wetland on the Great Lakes. The net change framework has implications for linkages between suitable habitat supply and fish population dynamics. Area fish habitat management plans envisioned in the policy and site-level net change assessments are connected. Quantitative ways are proposed for simultaneous assessment of NNL and "harmful alteration, disruption, or destruction" of fish habitat, as required in the Canadian Fisheries Act. Defensible methods for applying the net change equation are superior to earlier nonquantitative approaches. If the available science is insufficient, the precautionary principle is recommended. Future development steps for the quantitative net change framework are suggested.

[1]  R. Beamish,et al.  Climate change and northern fish populations , 1995 .

[2]  M. Schrenzel,et al.  Differential production of interferon-γ and interleukin-4 in response to Th1- and Th2-stimulating pathogens by γδ T cells in vivo , 1995, Nature.

[3]  W. Ricker.  Computation and interpretation of biological statistics of fish populations , 1977 .

[4]  J. Downing,et al.  Production of Fish Populations in Lakes , 1993 .

[5]  D. Canfield,et al.  A Phosphorus-Fish Standing Crop Relationship For Streams? , 1991 .

[6]  G. Phillips,et al.  THE MONITORING OF ECOLOGICAL QUALITY AND THE CLASSIFICATION OF STANDING WATERS IN TEMPERATE REGIONS: A REVIEW AND PROPOSAL BASED ON A WORKED SCHEME FOR BRITISH WATERS , 1996 .

[7]  C. Thomas.  Extinction, colonization, and metapopulations: environmental tracking by rare species , 1994 .

[8]  S. Garcia.  The Precautionary Principle: its implications in capture fisheries management , 1994 .

[9]  L. M. Dickie,et al.  Biological Model of Fisheries Production Based on Physiological and Ecological Scalings of Body Size , 1989 .

[10]  R. G. Randall,et al.  Detecting the response of fish to habitat alterations in freshwater ecosystems , 1996 .

[11]  L. M. Dickie,et al.  Biomass Spectra of Aquatic Ecosystems in Relation to Fisheries Yield , 1992 .

[12]  P. Lawton,et al.  The Interface between Fisheries Research and Habitat Management , 1996 .

[13]  C. K. Minns.  Approaches to assessing and managing cumulative ecosystem change, with the Bay of Quinte as a case study: an essay , 1995 .

[14]  D. Pauly,et al.  Primary production required to sustain global fisheries , 1995, Nature.

[15]  K. Radway Allen,et al.  Relation Between Production and Biomass , 1971 .

[16]  R. G. Randall,et al.  A model simulating the impact of habitat supply limits on northern pike, Essox lucius, in Hamilton Harbour, Lake Ontario , 1996 .

[17]  P. Pearse.  Turning the tide : a new policy for Canada's Pacific fisheries : final report / the Commission on Pacific Fisheries Policy, Peter H. Pearse, Commissioner. , 1982 .

[18]  J. Vallentyne,et al.  Special Contribution: Managing the Great Lakes Basin as a Home , 1986 .

[19]  R. Beverton,et al.  On the dynamics of exploited fish populations , 1993, Reviews in Fish Biology and Fisheries.

[20]  Oceans,et al.  Management of Marine Fisheries in Canada , 1993 .

[21]  A. Duncan,et al.  Methods for the estimation of production of aquatic animals , 1972 .

[22]  A. Stebbing.  Environmental capacity and the precautionary principle , 1992 .

[23]  B. Shuter,et al.  Toward a definition of conservation principles for fisheries management , 1997 .

[24]  A simulation model of how life history strategies mediate pollution effects on fish populations , 1993 .

[25]  J. Kelso,et al.  Factors Related to the Biomass and Production of Fish Communities in Small, Oligotrophic Lakes Vulnerable to Acidification , 1991 .

[26]  R. G. Randall,et al.  Fish production in freshwaters : are rivers more productive than lakes ? , 1995 .