Terms of Reference

Newly Discovered Howe Sound Glass Sponge Complexes: locations, status, and ecological significance assessment

Science Response Process – Pacific Region

December, 2017
Nanaimo, British Columbia

Chairperson: Anya Dunham

Context

In 2010, Canada agreed to marine conservation targets established under the United Nations Convention on Biological Diversity to conserve 10 percent of coastal and marine areas through effectively managed networks of protected areas and other effective area-based conservation measures by 2020. This is commonly referred to as Aichi Target 11. This commitment was reconfirmed in 2015 by the United Nations General Assembly’s 2030 Agenda for Sustainable Development under Goal 14.

Canada’s National Conservation Plan was launched in 2011 to advance progress in three priority areas, which includes conserving and restoring Canada’s lands and waters through safeguarding and enhancing biodiversity and ecosystems through conservation and stewardship actions.  The plan to meet these targets includes advancing Other Effective Area-Based Conservation Measures, such as fisheries closures, to protect sensitive sponge and coral concentrations. To that end, Fisheries Management committed to implementing at least five new conservation-based fisheries closures by 2020.

Glass sponge reefs are unique habitats found along the Pacific coast of Canada and the United States with intrinsic, ecological, and economic value. They provide a link between benthic and pelagic environments, play an important role in carbon and nitrogen processing, and act as silica sinks. While a full understanding of their ecological role is yet to be realized, diverse communities of invertebrates and fish, including those of economic importance, have been documented in association with the reefs (Cook et al. 2008, Marliave et al. 2009, Chu and Leys 2010, DFO 2017).

Over the past 15 years, nine glass sponge reef complexes have been discovered and mapped by the Canadian Hydrographic Service in the Strait of Georgia and Howe Sound using remote sensing (Conway et al. 2004; Conway et al. 2005; Conway et al. 2007; K. Conway, pers. comm.). In 2014, DFO requested that fishers using bottom-contact gear (prawn trap, crab trap, shrimp trawl, groundfish trawl and hook-and-line), voluntarily avoid these nine glass sponge reef areas while DFO consulted on formal protection measures.  After reviewing important input from the consultation process with First Nations, commercial and recreational fishers and conservation organizations, DFO proceeded with formal fishery closures to protect the nine glass sponge reef complexes in the Strait of Georgia and Howe Sound, effective June 12, 2015. Beginning April 1, 2016, the closures also apply to First Nations Food, Social, and Ceremonial fisheries.  In 2017, a CSAS review of quantitative assessment methods, outputs, and monitoring advice developed by DFO Science for these nine reef complexes has been completed (Dunham et al. 2017).

Recently, 13 other glass sponge aggregations (suspected to be glass sponge reefs and/or gardens) were discovered and identified by the Marine Life Sanctuaries Society (MLSS) and volunteer divers. In 2016, MLSS shared these locations with DFO Science; a collaborative project between DFO Science, Natural Resources Canada, and MLSS was initiated to further map and characterize these glass sponge areas.

DFO Fisheries Management has requested advice from the Science Branch characterizing the biological significance of the newly discovered sponge reefs in Howe Sound.  The assessment, and advice arising from this Canadian Science Advisory Secretariat (CSAS) Science Response Process (SR), will be used to inform management decisions regarding adaptive management and future monitoring of the sponge reefs in Howe Sound and to respond to stakeholder requests for scientific information on the sponge reefs. It is also expected to contribute to Canada's Marine Conservation Target (MCT) to protect 10% of Canada's coast by 2020

Objective

The specific objectives of this review are to:

1. Map the geological extent of the glass sponge reefs in Howe Sound using available multibeam bathymetry data.
2. Map and characterize the modern ecological extent (reef-forming glass sponge cover) using available visual survey data (diver video and records from MLSS, DFO ROV survey data).
3. Characterize megafaunal communities associated with these reef complexes.
4. Characterize ecological function of the glass sponge reefs using best available knowledge on the reefs in Howe Sound and elsewhere along the coast of British Columbia.
5. Provide advice on the potential benefits of protection.

Expected Publications

• Science Response

Expected Participation

• Fisheries and Oceans Canada (Ecosystems Management, Fisheries Management, Science)
• Natural Resources Canada
• Marine Life Sanctuaries Society

References

Chu JWF, Leys SP (2010) High resolution mapping of community structure in three glass sponge reefs (Porifera, Hexactinellida). Marine Ecology Progress Series 417: 97-113.

Conway KJ, Barrie V, Krautter M (2004) Modern siliceous sponge reefs in a turbid, siliciclastic setting: Fraser River delta, British Columbia, Canada. Neues Jahrbuch fur Geologie und Palaontologie-Monatshefte:335-350.

Conway KW, Barrie JV, Krautter M (2005) Geomorphology of unique reefs on the western Canadian shelf: sponge reefs mapped by multibeam bathymetry. Geo-Marine Letters 25:205-213.

Conway KW, Barrie JV, Hill PR, Austin WC, Picard K (2007) Mapping sensitive benthic habitats in the Strait of Georgia, coastal British Columbia: deep-water sponge and coral reefs. Geol. Surv. Can. 2007-A2:1-6.

Cook SE, Conway KW, Burd B (2008) Status of the glass sponge reefs in the Georgia Basin. Marine Environmental Research 66 (Suppl 1): S80–S86.

DFO. 2017. Glass Sponge Reefs in the Strait of Georgia and Howe Sound: Status assessment and ecological monitoring advice. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2017/026

Dunham A., Mossman J, Archer S., Pegg J, Archer E (2017) Glass Sponge Reefs in the Strait of Georgia and Howe Sound: Status assessment and ecological monitoring advice. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/xxxx (in press)

Marliave JB, Conway KW, Gibbs DM, Lamb A, Gibbs C (2009) Biodiversity and rockfish recruitment in sponge gardens and bioherms of southern British Columbia, Canada. Marine Biology 156, 2247-2254.