Quantifying “no net loss” of productivity of fish habitats

1997 ◽  
Vol 54 (10) ◽  
pp. 2463-2473 ◽  
Author(s):  
C K Minns
Keyword(s):  
Habitat Management ◽  
Coastal Wetland ◽  
Fish Habitat ◽  
Fish Population ◽  
Suitable Habitat ◽  
Productive Capacity ◽  
No Net Loss ◽  
Heterogeneous Habitats ◽  
The Difference ◽  
Change Framework

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.

Direct and indirect estimates of the productive capacity of fish habitat under Canada’s Policy for the Management of Fish Habitat: where have we been, where are we now, and where are we going?

2011 ◽  
Vol 68 (12) ◽  
pp. 2204-2227 ◽  
Author(s):  
Charles K. Minns ◽  
Robert G. Randall ◽  
Karen E. Smokorowski ◽  
Keith D. Clarke ◽  
Antonio Vélez-Espino ◽  
...  
Keyword(s):  
Habitat Management ◽  
Method Development ◽  
Dynamic Models ◽  
Fish Habitat ◽  
Assessment Tools ◽  
Management Policy ◽  
Productive Capacity ◽  
No Net Loss ◽  
Future Direction ◽  
And Function

No net loss of productive capacity (PC) of fish habitat has been the central concept guiding Canadian fish habitat management policy since 1986. The purpose of this paper is to describe the concept of PC, to review the history and application of the fish habitat management policy in Canada, and to provide a critical review of the range of potential approaches to estimating PC. The approaches were grouped by their central focus: habitat, individual, population, and community–ecosystem. A set of case studies is used to illustrate the use of some approaches drawn from freshwater and marine contexts. Ten components to assessing no net loss of PC were developed and used in the review of approaches for evaluating potential limitations. The review also highlighted the likely future direction of method development, with increasing emphasis on dynamic models integrating population responses to habitat supply characteristics. More work needs to be done to turn research-based metrics of PC into practical operational management assessment tools and to better quantify the link between habitat structure and function and fisheries productivity. The evolving approaches to measure PC reinforce the ties that fish habitat management has to the emerging practices in ecosystem-based management.

Assessment of net change of productive capacity of fish habitats: the role of uncertainty and complexity in decision making

2003 ◽  
Vol 60 (1) ◽  
pp. 100-116 ◽  
Author(s):  
Charles K Minns ◽  
James E Moore
Keyword(s):  
Decision Making ◽  
Habitat Management ◽  
Fish Habitat ◽  
Productive Capacity ◽  
No Net Loss ◽  
Habitat Linkages ◽  
Fish Habitats ◽  
Fish Response ◽  
Lake Habitats

Canada's fish habitat management is guided by the principle of "no net loss of the productive capacity of fish habitat" (NNL). Many development proposals are assessed using habitat information alone, rather than fish data. Because fish–habitat linkages are often obscured by uncertainty, uncertainty must be factored into NNL assessments. Using a quantitative framework for assessing NNL and lake habitats as a context, the implications of uncertainty for decision making are examined. The overall behaviour of a net change equation given uncertainty is explored using Monte Carlo simulation. Case studies from Great Lakes development projects are examined using interval analysis. The results indicate that uncertainty, even when large, can be incorporated into assessments. This has important implications for the habitat management based on NNL. First, schemas to specify relative levels of uncertainty using simple habitat classifications can support robust decision making. Second, attaining NNL requires greater emphasis on minimizing habitat loss and creating new areas to compensate for losses elsewhere and less on detailing small incremental changes in modified habitats where the fish response is difficult to demonstrate. Third, the moderate to high levels of uncertainty in fish–habitat linkages require that created compensation is at least twice the losses to reasonably ensure NNL.

Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
Lake Erie ◽  
Habitat Management ◽  
Fish Habitat ◽  
Learning By Doing ◽  
Suitable Habitat ◽  
Physical Habitat ◽  
Fish Stocks ◽  
Habitat Features ◽  
Fish Habitats

<em>Abstract.—</em> The quality and quantity of habitats determine ecosystem productivity. Hence, they determine the potential fish productivity that sustains the fish harvests extractable from freshwaters and seas. Efforts to conserve and protect fish habitats are frustrated by key unanswered questions: which habitat types and how much must be protected to ensure natural self-sustaining fish stocks? Minns and Bakelaar presented a prototype method for assessing suitable habitat supply for fish stocks in Lake Erie, an analysis that can be used to address conservation issues. Here, the method is refined and extended, taking the assessment of habitat supply for pike <em>Esox lucius </em> in the Long Point region of Lake Erie as a case study. As with the previous study, much emphasis is placed on “learning by doing.” Because available inventories of habitat features are coarse and incomplete, improved guidelines for estimating habitat supply are expected from these prototype studies. The habitat supply method previously presented by Minns and Bakelaar is elaborated in three ways here: (1) the basic physical habitat assessment is derived from a remote-sensing inventory database; (2) methods of quantifying the thermal regime and integrating it with other habitat elements are examined; (3) habitat supply estimates are used in a pike population model, and pike biomass and production are simulated for the Long Point region of Lake Erie and then compared with available records. The roles of error and uncertainty are examined for all elements in the estimation and application of suitable habitat supply values. There is potential for supply measurement and analysis to guide fish habitat management.

scholarly journals Waterbird habitat loss fringing the Yellow and Bohai seas along the East Asian--Australasian migratory flyway

2021 ◽  
Author(s):  
Houlang Duan ◽  
Xiubo Yu ◽  
Shaoxia Xia ◽  
Guangshuai Zhang
Keyword(s):  
Habitat Management ◽  
Coastal Wetland ◽  
Species Distribution Model ◽  
Tidal Flats ◽  
Distribution Model ◽  
Suitable Habitat ◽  
Natural Wetland ◽  
Artificial Wetlands ◽  
Waterbird Species ◽  
Salt Pan

Natural wetland along the coasts of Yellow and Bohai seas provided key stopover sites for migratory waterbirds. However, these wetlands are facing land loss. Understanding how natural wetlands loss influence habitat is an important step for habitat management. Using species distribution model to report changes in area of suitable habitat, and the effects of natural wetland loss on habitat for 80 waterbird species attributed to four functional categories (shorebird, duck, heron, gull), between 2000 and 2015 in the Yellow and Bohai seas. Of 1794.8 km2 of coastal wetland lost to development between 2000 and 2015, most represented tidal flats converted into aquaculture and salt pan habitat, or for construction. Consequently, habitat for 73 of these 80 species has decreased in area over this time period. Generally, the proportional decline in habitat suitable for species of duck was less than it was shorebirds, herons and gulls. The proportional loss of tidal flat habitat that formerly represented suitable habitat for shorebirds, herons and gulls was also significantly higher than it was for ducks. Because more species of duck exploit aquaculture and salt pan habitat converted from tidal flats than do shorebird, heron and gull species, such conversion of tidal flats pose a greater threat to shorebirds, herons and gulls than they do to ducks. Preventing further reclamation of tidal flats and managing artificial wetlands are priorities for waterbirds conservation, especially for the species ducks.

Fish habitat management implications of the summer habitat use by littoral fishes in a north temperate, mesotrophic lake

2003 ◽  
Vol 60 (3) ◽  
pp. 286-300 ◽  
Author(s):  
Thomas C Pratt ◽  
Karen E Smokorowski
Keyword(s):  
Habitat Heterogeneity ◽  
Habitat Management ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Distinct Species ◽  
Habitat Associations ◽  
Productive Capacity ◽  
Habitat Types ◽  
Habitat Directive ◽  
Rocky Habitats

Compensation measures in response to Fisheries and Oceans Canada (DFO) Policy for the Management of Fish Habitat includes provisions for habitat creation and enhancement. Thus, an assessment of nearshore habitat utilization patterns by fishes is needed to put DFO compensation measures in the context of the "no net loss of the productive capacity of fish habitat" directive. Measures of abundance, richness, and diversity of fishes were compared across nine habitat types in a lake using rapid visual underwater assessment. Multivariate analyses separated habitats into three groups and identified two distinct species assemblages. Most species were associated with macrophytes, but a few were primarily associated with rocky substrate. Shallow mud (open) habitats contained significantly fewer species and had lower mean scores and diversity than all other habitat types. Rocky habitats had lower mean scores and diversity than some vegetated habitat types containing similar fish assemblages. Surprisingly, within-site fish assemblage heterogeneity was similar to among-site heterogeneity, and among-habitat heterogeneity was lower than within-habitat heterogeneity, further supporting our inability to distinguish among vegetated habitat types. Our results suggest that habitat heterogeneity is critical in maintaining diverse communities and that compensation measures should account for differences in fish–habitat associations among varied habitats.

Compensation ratios needed to offset timing effects of losses and gains and achieve no net loss of productive capacity of fish habitat

2006 ◽  
Vol 63 (5) ◽  
pp. 1172-1182 ◽  
Author(s):  
Charles K Minns
Keyword(s):  
Fish Habitat ◽  
Time Frame ◽  
Development Project ◽  
Productive Capacity ◽  
Habitat Alterations ◽  
No Net Loss ◽  
Future Discounting ◽  
Timing Effects ◽  
Fish Habitats

Minns' (Can. J. Fish. Aquat. Sci. 54: 2463–2473 (1997)) framework for assessing net change of productive capacity of fish habitats in Canada is expanded to include the effect of timing of losses and gains on cumulative net change. The expansion requires establishment of a reference time frame for assessment. A time frame of twice the project's duration is recommended. Delaying compensation actions while incurring losses early in a project increases the levels of compensation required. The addition of future discounting had much less effect on compensation requirements than the effects resulting from timing differences between losses and compensation. As discounts apply equally to losses and gains, they likely balance out over time. Delays between when habitat alterations occur and when expected productive capacity is attained increase the required compensation. There are advantages to starting compensation efforts early in a development project. A case study of a hypothetical northern diamond mine shows how various components of compensation (replacement, uncertainty, and timing) can be integrated when assessing net change. Consideration of all components of compensation indicates the need for tougher precautionary compensation guidelines with ratios greater than the current 1:1. Values of 2:1 or higher may be necessary to ensure attainment of Canada's guiding policy principle of no net loss.

Managing the Impacts of Human Activities on Fish Habitat: The Governance, Practices, and Science

2015 ◽  
Keyword(s):  
Habitat Suitability ◽  
Fish Habitat ◽  
Individual Development ◽  
Global Changes ◽  
Human Society ◽  
Productive Capacity ◽  
No Net Loss ◽  
Governance Practices ◽  
Ecosystem Level ◽  
Primary Focus

<em>Abstract.</em>—Efforts to achieve no net loss of productive capacity (PC) of fish habitat are failing in Canada and elsewhere. These growing losses, particularly in freshwaters, have a central role in ongoing global changes that threaten our future. Canada has a large share of global freshwater resources and hence a greater responsibility to help find solutions. For fish habitat, a preoccupation with habitat suitability, and other indices of that ilk, has diverted attention from self-sustaining fish populations, their productivity, and their fisheries. Symptoms of the problem are reviewed and a remedial approach is offered alongside analogies from comparable conservation and protection arenas such as fisheries, biodiversity, and human society. Many of the symptoms of failure arise from the primary focus of management efforts at the level of individual development activities while the remedies require a focus on more holistic ecosystem-level strategies. Implementation of these remedial approaches is considered.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Habitat Management ◽  
Research Council ◽  
Fish Habitat ◽  
Effective Interaction ◽  
National Research Council ◽  
Fishing Effort ◽  
Socioeconomic Impacts ◽  
Management Measures ◽  
Management Plans ◽  
Existing Data

<strong><em>Abstract. </em></strong>This paper summarizes the results of the National Research Council Study on the Effects of Bottom Trawling and Dredging on Seafloor Habitat (National Research Council 2002). The report concludes that integration of existing data on the effects of trawls and dredges, level of fishing effort, and distribution of seafloor habitats would facilitate development of habitat management plans. Current and new management measures should be assessed regularly to provide a better understanding of how various restrictions affect fish habitat and to determine the socioeconomic impacts on the fishing industry and local communities. Resolution of the different, and at times conflicting, ecological and socioeconomic goals will require not only a better understanding of the relevant ecosystems and fisheries but also more effective interaction among stakeholders.

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