Terms of Reference

Identification and Evaluation of Biological Effects and Impacts of Sediment to Sponge Communities in Hecate Strait

Pacific Regional Science Advisory Process

October 23-25, 2012
Nanaimo, BC

Chairperson: Linda Nichol

Context

The Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs have been identified as an ecologically and biologically significant area due to their global geological uniqueness (Conway et al. 1991, Conway et al. 2001 & Kruatter et al. 2001), and there is international and national recognition that cold-water corals and sponge dominated communities can serve as key structural habitat for many fish and invertebrate species (DFO 2010). This area is currently in the process of being designated as an Oceans Act Marine Protected Area (MPA) as part of the Health of the Oceans Initiative. It has been identified as an Area of Interest in consideration of an ecosystem-based management (EBM) approach for the Pacific North Coast Integrated Management Area (PNCIMA), within which the reefs are located.

The proposed MPA consists of three separate areas totalling 2410 square kilometres that include the four glass sponge reef complexes located in Hecate Strait and Queen Charlotte Sound, the water column and the surrounding waters, and the seabed and subsoil to a depth of 20 meters. The three areas are referred to as the Northern Reef, the Central Reef (containing two reef complexes), and the Southern Reef. Each of the three areas is proposed to have three internal management zones, referred to as the Core Protection Zone (CPZ), the Adaptive Management Zone (AMZ) and the Vertical Adaptive Management Zone (VAMZ).

Understanding both direct and indirect stressors from activities is key to the implementation of ecosystem-based management. Indirect effects due to resuspension of sediment from human activities may affect sponge communities, including hexactinellid ‘glass’ sponges (Conway et al. 2001, Whitney et al. 2005, Austin et al. 2007, Yahel et al. 2007, Tompkins-MacDonald & Leys 2008), however, the nature and extent of these effects is unclear. As some activities that resuspend sediment due to contact with the bottom may be permitted in the AMZ, DFO Ecosystem Management Branch Pacific Region has requested DFO Science Pacific Region to provide an assessment of the nature and extent of the potential effects of sedimentation on glass sponge reefs and recommend mitigation measures for activities/areas where there risks to these communities are identified.

A risk-based assessment framework, previously reviewed through the Canadian Science Advisory Secretariat (CSAS), will be utilized to identify activities likely to create sedimentation in the AMZ and evaluate the nature and extent their potential risk to these sponge communities (O et. al. in prep.). This risk-based framework is a tool that assists in the identification of priorities, conservation objectives, management strategies and action plans including monitoring, research and management assessments as appropriate. This assessment will then be utilized to propose and evaluate possible mitigation measures. The value of this risk-based framework is that it allows for a transparent process for gathering, evaluating and recording information related to the risk of harm from human activities/stressors on the glass sponge communities.

Objectives

The objective of this science advisory process is to:

1. Identify and evaluate the biological effects and impacts of sediment on sponge communities in Hecate Strait (Working Paper 1);
   
   
2. To identify those activities that could occur in the adaptive management zone that could impact the sponge reefs through re-suspension of sediment (Working Paper 2), and;
   
   
3. To identify mitigation measures for relevant activities and impacts (Working Paper 2).

The following working papers will be reviewed to provide the basis for discussion and advice:

The effects of sediment on glass sponge reefs. Leys, S.P. Centre for Science Advice - Pacific (CSAP) Working Paper 2012/P44a.

Paper overview: Summary of knowledge of the nature sedimentation effects on sponge communities, with a specific focus on the effects of sediment on glass sponge communities in general and Hecate Strait sponge reef communities in particular.

An Ecological Risk Assessment Framework for fisheries induced resuspended sediment impacts on Hecate Strait glass sponge reefs. Boutillier, J. CSAP Working Paper 2012/P44b.

Paper overview: Discussion of extent of the potential impacts and a discussion of various mitigation measures that may reduce the extent of the impact. This will address what activities are likely to resuspend sediment (look at Pathways of Effects (PoEs) and quantify effects), and the potential extent of the impacts (question 3 from original request) considering the currents, sediment, and nature of the activity.

Considerations for the review of these working papers include:

Objective i - Working Paper 1:

1. Completeness of information provided and summarized regarding the effects of sediment on sponge communities.
2. Accuracy of identified effects of sediment on the sponge communities in Hecate Strait (particularly to hexactinosidian ‘glass’ sponges).

Objective ii - Working Paper 2:

1. Completeness of the PoEs evaluation.
2. Soundness of the ocean current modelling and results describing the potential distribution of suspended sediments.

Objective iii – Working Paper 2:

1. Effectiveness of suggested mitigation measures to address the identified effects.

Expected publications

• CSAS Proceedings
• CSAS Science Advisory Report (1)
• CSAS Research Documents (2)

Participation

• DFO Science
• DFO Oceans
• DFO Habitat
• DFO Species at Risk
• DFO Fisheries Management
• Province of BC
• Fish harvester experts
• Environmental Non-governmental Organisations experts
• Academic experts

Additional Information and References Cited

Austin, W.C., Conway, K.W., Barrie, J.V. and Krautter, M. 2007. Growth and morphology of a reef-forming glass sponge, Aphrocallistes vastus (Hexactinellida), and implications for recovery from widespread trawl damage. Porifera Research: Biodiversity, Innovation and Sustainability. 139-145.

Conway, K.W., Krautter, M., Barrie, J.V. and Neuweiler, M. 2001. Hexactinellid sponge reefs on the Canadian continental shelf: A unique “living fossil”. Geoscience Canada. 28(20): 71-78.

Conway, K.W., Barrie, J.V., Austin, W.C., and Luternauer, J.L. 1991. Holocene sponge bioherms on the western Canadian continental shelf. Continental Shelf Research. 11(8-10): 771-790.

DFO. 1999. Hexactinellid Sponge Reefs on the British Columbia Continental Shelf: Geological and Biological Structure with a Perspective on their Role in the Shelf Ecosystem. DFO. Can. Sci. Advis. Sec. Res. Doc. 1999/192.

DFO. 2002. Hexactinellid Sponge Reefs: Areas of Interest as Marine Protected Areas in the North and Central Coast Areas. DFO. Can. Sci. Advis. Sec. Res. Doc. 2002/122.

DFO. 2010. Pacific Region Cold-Water Coral and Sponge Conservation Strategy 2010-2015. Fisheries and Oceans Canada. 2010/1663.

Krautter, M., Conway, K., Barrie, J.V., and Neuweiler, M. 2001. Discovery of a “living dinosaur”: globally unique modern Hexactinellid sponge reefs off British Columbia, Canada. Facies. 44: 265-282.

Leys, S.P., Wilson, K., Holeton, C., Reiswig, H.M., Austin, W.C., and Tunnicliffe, V. 2004. Patterns of glass sponge (Porifera, Hexactinellida) distribution in coastal waters of British Columbia, Canada. Mar Ecol Prog Ser. 283: 133-149.

O, M., Martone, R., Hannah, L., Greig, L., Boutillier, J. and Patton, S. 2012. An Ecological Risk Assessment Framework (ERAF) for Ecosystem-based Oceans Management. CSAP Research Working Paper presented May 8-10, Nanaimo, BC.

Tompkins-MacDonald, G.J. and Leys, S.P. 2008. Glass sponges arrest pumping in response to sediment: implications for the physiology of the hexactinellid conduction system. Mar Biol. 154: 973-984.

Whitney, F., Conway, K., Thomson, R., Barrie, V., Krautter, M., and Mungov, G. 2005. Oceanographic habitat of sponge reefs on the Western Canadian Continental Shelf. Continental Shelf Research. 25: 211-226.

Yahel, G., Whitney, F., Reiswig, H.M., Eerkes-Medrano, D.I., and Leys, S.P. 2007. In situ feeding and metabolism of glass sponges (Hexactinellida, Porifera) studied in a deep temperate fjord with a remotely operated submersible. Limnol. Oceanogr. 52(1): 428-440.