Science Advisory Report  2015/007

Characterization of Fishery Effects on Significant Ecosystem Components of the proposed Scott Islands marine National Wildlife Area

Summary

• The Scott Islands marine National Wildlife Area (SImNWA) is being established to protect the marine habitat of the largest and most diverse seabird colony in Pacific Canada. Environment Canada (EC) is the lead agency for the establishment of NWAs while Fisheries and Oceans Canada (DFO) has the regulatory authority for the management of fisheries within NWAs.
• An evaluation was conducted of the data, information, and analyses available and needed to support both qualitative and quantitative ecological risk assessments of commercial fishing activities in the proposed SImNWA.  The evaluation was structured using the Ecosystem Risk Assessment Framework (ERAF) developed to support marine spatial planning in Pacific waters by DFO (DFO 2012). The ERAF incorporates the Pathways of Effects (PoE) approach to assessing stressor impacts on significant ecosystem components (SECs).
• The evaluation provided illustrative examples of both the ecological consequences of commercial fishing, and the level of exposure from commercial fishing on representative species, habitat, and ecosystem/community property SECs that were selected for evaluation based on the proposed goals for the SImNWA (EC 2013).
• Fishing activities that may impact SECs, as illustrated through the PoE approach, have historically occurred and continue to occur, in SImNWA.  Stressors from these activities include direct mortality of seabirds (species SECs), mechanical disruption and settling of remobilized sediments on physical and biogenic habitats that support seabirds or their essential prey organisms (habitat SECs), and alterations in food web dynamics through the provision of alternative food sources resulting from the discarding of bait, non-target catch, and offal, and other fishing practices (ecosystem/community property SEC).
• Bycatch data on seabirds, invertebrates, and non-commercial fish species are inconsistently collected in fisheries managed by DFO. The Groundfish sector is relatively information-rich because mechanisms are in place to collect bycatch data, including seabirds, as a condition of licence, although the identification of bycatch to species is limited and would benefit from the development of appropriate identification methods and tools.  Other sectors (Salmon, Invertebrates, and Pelagics) either have no reporting requirement, or have not established a standardized data collection protocol for bycatch species, and are therefore information-poor.
• None of the existing commercial fishery bycatch programs regularly provide bycatch information at the scale of species or population. As a result, an evaluation of the risks resulting from bycatch impacts on species SECs in the SImNWA cannot be conducted at present. It is recommended that a list of available information on the exposure and consequence of direct bycatch mortality be compiled for bycatch species.
• Identification of seabirds and other bycatch organisms (e.g., fish, invertebrates) captured by all fishing activities is a prerequisite for a comprehensive ERAF assessment in SImNWA. However, proper identification of bycatch, beyond well-known fish species, is an important information gap in fisheries managed by DFO in Pacific Region. To address bycatch data gaps in commercial fisheries, a standardized protocol for the collection of bycatch data (location, date, number) along with methods and tools to support identification to species or population where appropriate, and system(s) to manage bycatch data, are necessary. Development of this collection protocol and supporting tools could be informed by the data needs of other agencies with marine spatial planning and management responsibilities.
• Assessing exposure to stressors and the consequences of stressors from human activities may be relevant at the population level for some species SECs because risk may not be shared equally among populations. Some species SECs have distinct populations in or near the SImNWA, and other species SECs are part of larger pan-Pacific or global seabird populations. It is recommended that population SECs within a species be identified, if appropriate, when conducting a comprehensive ecosystem risk assessment.
• The risks associated with mechanical disruption and settling of remobilized sediments on physical and biogenic habitat SECs in SImNWA are probably confined to benthic features that support important prey species of seabirds. These risks were not assessed because there are information gaps with respect to the proper identification of prey species, such as juvenile rockfish (and their habitats), in seabird diet studies and fishery bycatch programs, in the importance of different prey species to seabirds within SImNWA, particularly in terms of critical life history events such as fledging survival, and the impacts of fishing gear on different bottom types. Research is ongoing to identify habitat types important to Pacific Sand Lance (Ammodytes hexapterus), which is a significant seabird (and fish) prey species, and whose abundance in diets has been related to fledgling survival of some seabird species in SImNWA.
• The impact of discards of bycatch and offal by commercial fishing activities described in a case study of the North Sea was used to identify, by analogy, the type of risks that might result from shifts in the trophodynamics of ecosystem/community property SECs within the SImNWA. While the results are not conclusive, they point to the importance of distinguishing between natural variation in seabird predators, and their seabird prey species, and those variations caused by human activities, in order to comprehensively assess the risk to ecosystem SECs. Monitoring all aspects of fishing activities (e.g., discards of target, non-target, and other bycatch species), and all predator and prey species, will be required to conduct a comprehensive ERAF assessment in the SImNWA.
• This evaluation exercise considered exposure and consequence from a single type of human activity (commercial fishing gear), and did not consider the potential risk to SECs from multiple stressors, or cumulative impacts. A broader evaluation across all human activities and potential stressors will be needed for a comprehensive ecosystem risk assessment in support of integrated ecosystem management planning in SImNWA.
• The ERAF (DFO 2012) provides a useful structure to take into account ecosystem considerations and to highlight the data needs (and current gaps) of a comprehensive ecosystem risk assessment. The results heighten awareness of the importance of conducting a systematic and well-documented scoping phase before entering into a comprehensive system analysis with the ERAF.
• Additional data gaps and research needs were identified for each type of SEC, including identifying and monitoring seabird populations and prey fish populations, further work to identify suitable habitat SECs within the SImNWA, and continued annual monitoring of the state of the ecosystem, among others.

This Science Advisory Report is from the August 6-7, 2014 meeting on Characterization of Fishery Effects on Valued Species, Habitat, and Ecosystem Components of the Proposed Scott Islands Marine National Wildlife Area. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

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