Robert G. Randall

Comparison of a Habitat Productivity Index (HPI) and an Index of Biotic Integrity (IBI) for Measuring the Productive Capacity of Fish Habitat in Nearshore Areas of the Great Lakes

Abstract A Habitat Productivity Index (HPI) and an Index of Biotic Integrity (IBI) were compared as measures of habitat productive capacity for fish assemblages in nearshore areas of Lake Erie and Lake Ontario. Forty-three species of fishes were captured by boat electrofishing at three areas with contrasting habitats—coastal wetlands, harbor breakwalls, and exposed shorelines. HPI and IBI were correlated among samples as expected, but HPI was most closely correlated with fish community biomass, whereas IBI was correlated with fish species richness. The HPI and IBI indices differed significantly among samples from the three habitat areas in both lakes, reflecting the differences in the abundance and composition of fish catches. The ranking of habitat productive capacity depended on the index: species richness and IBI were highest at the coastal wetlands, and biomass and HPI were highest at the harbors. Results support the contention that to effectively determine habitat productive capacity, both the production and diversity characteristics of the fish community need to be evaluated.

Fish community indices of ecosystem health: How does the Bay of Quinte compare to other coastal sites in Lake Ontario?

The Index of Biotic Integrity (Minns et al., 1994) was used to evaluate ecosystem health in the Bay of Quinte, Lake Ontario. Despite being classified an Area of Concern (AOC) in 1985, Index of Biotic Integrity (IBI) values at Bay of Quinte fell within the range or exceeded values from reference locations elsewhere in Lakes Ontario and Erie. Fish survey data collected from 1988–2009 in the Bay of Quinte and elsewhere indicated that (1) the Bay of Quinte has relatively healthy fish habitat despite the AOC designation, (2) Bay of Quinte IBI scores increased significantly between 1990 and 1999 due to changes in relative species richness and (3) differences in fish communities were correlated with physical habitat attributes at survey locations. Data from both nearshore electrofishing and trap net surveys confirmed that the Bay of Quinte supports a highly productive and diverse fish community.

Stock assessment in inland fisheries: a foundation for sustainable use and conservation

Fisheries stock assessments are essential for science-based fisheries management. Inland fisheries pose challenges, but also provide opportunities for biological assessments that differ from those encountered in large marine fisheries for which many of our assessment methods have been developed. These include the number and diversity of fisheries, high levels of ecological and environmental variation, and relative lack of institutional capacity for assessment. In addition, anthropogenic impacts on habitats, widespread presence of non-native species and the frequent use of enhancement and restoration measures such as stocking affect stock dynamics. This paper outlines various stock assessment and data collection approaches that can be adapted to a wide range of different inland fisheries and management challenges. Although this paper identifies challenges in assessment, it focuses on solutions that are practical, scalable and transferrable. A path forward is suggested in which biological assessment generates some of the critical information needed by fisheries managers to make effective decisions that benefit the resource and stakeholders.

The Science Framework for Implementing the Fisheries Protection Provisions of Canada's Fisheries Act

In 2012, Canadas Fisheries Act was amended. New fisheries protection provisions provide for the sustainability and ongoing productivity of commercial, recreational, and Aboriginal fisheries. These provisions replace previous provisions that focused on fish habitats, and concerns have been expressed that the amended Act has lowered aquatic habitat protection. The science framework developed for implementation of the new provisions is based on the relationships between fisheries productivity and the response of habitats or populations to pressures, with pressures linked to specific classes of activities through pathways of effects models. The framework includes guidance on quantifying productivity, scales and types of impacts, establishing equivalence in offsetting, and managing risk. Risk of failing to achieve the intent of the fisheries protection provisions is only managed when impacts of activities have a net neutral or positive effect on fisheries productivity. This standard applies whether the evalua...

Fish community structure in the Bay of Quinte, Lake Ontario: The influence of nutrient levels and invasive species

Intensive, long-term sampling in the Bay of Quinte with multiple gears (i.e. gill nets, bottom trawls, trap nets and boat electrofishing) allowed examination of the fish community and major fish populations in the context of key stressors up to 2009. Excessive nutrient input and hyper-abundant non-native fish species, White Perch and Alewife, shaped the depreciated fish community of the 1970s. After implementation of phosphorus input control measures and simultaneous winter-kills of the hyper-abundant non-native fish in the late 1970s, Walleye recovered and served to restore a predator-prey balance to the fish community by the late 1980s. However, in the absence of a significant recovery of submerged aquatic vegetation (SAV) in littoral areas, off-shore species (e.g. Alewife and White Perch) still tended to dominate; even in littoral areas. Following establishment of Dreissenid Mussels in the mid-1990s, water transparency increased and SAV increased significantly in littoral areas. This pivotal event led to a shift in the fish community that included an overall decline in Walleye, an increase followed by a decrease in Yellow Perch, and dominance by centrarchids (i.e. Bluegill, Pumpkinseed, Black Crappie and Largemouth Bass) in the nearshore. Round Goby invaded in 1999, proliferated and became important in the diet of piscivores by 2003. The current species assemblage, including the piscivores, is diverse and indicative of a healthy fish community.

NSERC's HydroNet: A National Research Network to Promote Sustainable Hydropower and Healthy Aquatic Ecosystems

Abstract NSERCs HydroNet is a collaborative national five-year research program initiated in 2010 involving academic, government, and industry partners. The overarching goal of HydroNet is to improve the understanding of the effects of hydropower operations on aquatic ecosystems, and to provide scientifically defensible and transparent tools to improve the decision-making process associated with hydropower operations. Multiple projects are imbedded under three themes: 1) Ecosystemic analysis of productive capacity offish habitats (PCFH) in rivers, 2) Mesoscale modelling of the productive capacity offish habitats in lakes and reservoirs, and 3) Predicting the entrainment risk of fish in hydropower reservoirs relative to power generation operations by combining behavioral ecology and hydraulic engineering. The knowledge generated by HydroNet is essential to balance the competing demands for limited water resources and to ensure that hydropower is sustainable, maintains healthy aquatic ecosystems and a vibr...

The fish community of Hamilton Harbour, Lake Ontario: Status, stressors, and remediation over 25 years

Hamilton Harbour is a large (21 km2) protected harbour located at the western end of Lake Ontario that was designated as an Area of Concern in 1985 by the International Joint Commission. As part of the designation, the fish community was deemed “impaired.” One of the long-term goals of the Hamilton Harbour Remedial Action Plan is to rehabilitate the fishery to a state, at least in part, to what it was prior to the degrading effects of industrial and municipal pollution, habitat loss, and invasive species. Since the Area of Concern designation, the nearshore fish community has been monitored regularly via a federal boat electrofishing program (1988–2013) and more recently, by a trap net program (2006–2012). During the study period, the harbour underwent significant physical and biological change which was related to both lake-wide (e.g. Dreissenids) and localized harbour events (e.g. habitat restoration). The fish community was assessed temporally using two indices of ecosystem health, the Great Lakes Index of Biotic Integrity and Proportion of Piscivore Biomass, and species-specific catch trends at unaltered sites or sites modified by habitat restoration. Early on, the fish community was dominated by tolerant species characteristic of degraded, eutrophic environments and piscivore abundance was low. The fish community responded positively to ecosystem actions during the first decade that improved water quality, increased physical habitat and reduced invasive species, but further progress was confounded by the interactions with other factors in the last decade that included new invasive species and a decline in water quality. Fish community assessments in the last decade, using both the indices found that the fish community was still impaired and dominated by non-native and pollution tolerant species. The Index of Biotic Integrity was a suitable indicator of ecosystem health strengthened by a consistent assessment with the Proportion of Piscivore Biomass index. A science based refinement of the existing Index in the future would benefit the ability to assess nearshore fish assemblages in the context of conservation goals.

Effect of aquatic macrophyte cover and fetch on spatial variability in the biomass and growth of littoral fishes in bays of Prince Edward County, Lake Ontario

Biomass and growth of Pumpkinseed ( Lepomis gibbosus), Yellow Perch ( Perca flavescens) and cohabiting species varied among different bays of Prince Edward County in eastern Lake Ontario. Biomass (B) and a calculated fish production (P) index of fishes, estimated as the product of average seasonal biomass and P/B, was about 6x higher at the electrofishing transects with medium to high macrophyte cover and low fetch than at sites where macrophytes were absent or sparse and fetch was high. The production index -aquatic plant relationship was species-dependent. The biomass component of fish production was related to macrophyte cover but the growth component and P/B (determined by allometry with body size) was not. Biomass and inferred production could be predicted from fetch, macrophyte abundance and water temperature, but with low precision. Results were consistent with index trawling in showing that changes in aquatic vegetation following Dreissena colonization in the Bay of Quinte and vicinity have affected the abundance of phytophilic fishes in this region of eastern Lake Ontario.

Linking the land and the lake: a fish habitat classification for the nearshore zone of Lake Ontario

Abstract: The nearshore zones of the Great Lakes provide essential habitat for biota and are perhaps the region of the lakes most susceptible to human impacts. The objective of our study was to develop a fish habitat classification for the nearshore zone of Lake Ontario based on physical characteristics of that zone, land cover in the surrounding watershed, and fish community patterns. Nearly 80% of the spatial variation in fish community data was described by 2 physical variables (average fetch and bathymetric slope of the nearshore zone) and 2 land-cover variables (urban/industrial development and mixed forest cover) in adjacent watersheds. These variables are likely to be surrogates for other conditions in the nearshore, such as wave action, circulation, vegetation, and water quality. A 12-group fish habitat classification was developed from those variables. Validation and significance tests identified similarities and differences among the fish communities in the classes and indicated that the number of classes should be collapsed to 3: exposed, sheltered, and developed/urbanized. In general, the western basin of the lake was developed, the central region was exposed, and the eastern region of the lake was a mix of exposed and sheltered classes. These results highlight that even in lakes as large as Lake Ontario, the nearshore fish community is influenced by watershed land cover, and emphasize that management or restoration of the nearshore ecosystem in lakes will require integration of aquatic, watershed, and land-cover management.

A comparison of approaches for integrated management in coastal marine areas of Canada with the historical approach used in the Great Lakes (Bay of Quinte)

Canadian approaches for ecosystem-based management in coastal marine areas, prompted by Canadas Oceans Act, are similar to and consistent with the long-standing, integrated management of the Bay of Quinte in Lake Ontario. The similarities include the criteria for the identification of ecologically significant areas and habitat, degraded areas, ecologically significant species, depleted or rare species, conservation objectives and ecological indicators to assess the status of ecosystem components. The rationale for integrated management in the Bay of Quinte is compared to marine areas, using the terminology that has been adopted for ocean area-based management in Canada. The three overarching goals of maintaining productivity, preserving biodiversity and protecting habitat are common to both freshwater and marine ecosystems. Communication of science priorities is mutually beneficial for advancing integrated management in both ecosystem types. Identifying the Bay of Quinte as a coastal management area by Great Lakes agencies, using elements of the oceans framework, would demonstrate a transition from a negative (degraded area) to a positive ecosystem status (essential habitat with high productivity and biodiversity).