Elaboración

Because most benthic fauna are sessile or have limited mobility, and because many taxa have life spans that range from years to decades, the species composition of the benthos can be an excellent indicator from which to measure environmental change over long time scales (Underwood 1996, Beuchel et al. 2006, Kedra et al. 2010). Long- term studies of benthic communities in cold waters and/or the Arctic have been documented in Arctic fjords around Svalbard, Norway (e.g. Dyer et al. 1984, Beuchel et al. 2006, Renaud et al. 2007, Beuchel and Gulliksen 2008, Kedra et

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al. 2010, Kortsch et al. 2012), the northern Bering Sea (Grebmeier et al. 2006), Fram

Strait (Taylor et al. 2017), the Chukchi Sea (Grebmeier et al. 2015), Alaska

(Blanchard et al. 2002), and the Barents and Kara Seas (Kiyko and Pogrebov 1997, Carroll et al. 2009, Kozlovskiy et al. 2011) but no longitudinal studies of the benthos have occurred in the Canadian Arctic aside from one study that looked at the direct impacts of an experimental release of oil on Arctic nearshore macrobenthos over a 4- year period in the early 1980s at Cape Hatt, northern Baffin Island (Cross et al. 1987, Cross and Thomson 1987; Figure 1.6; Table 1.1).

Figure 1.6. Coverage of long-term studies throughout the Arctic Seas. Figure acquired and adapted from

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Table 1.1. Summary of long-term studies of benthic communities and/or species conducted throughout the Arctic Seas.

Reference Arctic Sea Study Area Long-Term Benthic Project

Beuchel et al. 2006 and Beuchel and Gulliksen 2008

Greenland Sea Kongsfjord, Svalbard, Norway

24 year study (1980-2003) that examined temporal patterns of recolonization and disturbance in a hard bottom marine macrobenthic community.

Dyer et al. 1984 Greenland Sea Along western coastline

of Svalbard, Norway

Compared benthic invertebrate species sampled between 1949-1959 with samples collected between 1978-1981.

Kedra et al. 2010 Greenland Sea Kongsfjord, Svalbard,

Norway

Examined benthic macrofauna communities between 1997/1998 and 2006 along the fjord axis.

Kortsch et al. 2012 Greenland Sea Kongsfjord and

Smeerenburgfjord, Svalbard, Norway

Investigated changes in rocky-bottom community structure between 1980- 2010.

Renaud et al. 2007 Greenland Sea Van Mijenfjord, Svalbard, Norway

Examined changes in the soft-sediment benthic community from samples collected in 1980 and 2000/2001.

Grebmeier et al. 2006 Bering Sea Shallow shelf of the North Bering Sea

Demonstrate that an ecosystem shift has occurred with a displacement of marine mammal populations, reduction of benthic prey populations, and an increase pelagic fish coinciding with a reduction in sea ice, and increase in air and ocean temperatures.

Taylor et al. 2017 Greenland Sea HAUSGARTEN long-

Term Observatory, Fram Strait

Assessed temporal variability in structure, density, and diversity of megafaunal communities between 2004-2015.

Grebmeier et al. 2015 Chuchki Sea Throughout Southern Chukchi Sea

Examined macrofaunal and epifaunal composition and biomass and associated environmental drivers for time-series data collected in 2004, 2009, and 2012.

Blanchard et al. 2002 Gulf of Alaska Port Valdez, Alaska, USA Examined benthic faunal structure and hydrocarbon concentrations within the sediments over a ten year period (1989-1998).

Carroll et al. 2009 Barents Sea Southeastern Barents Sea Analyzed growth rates of the cockle Serripes groenlandicus for almost 70 years (1882-1968) to identify patterns and drivers of natural variability in the

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population and to gauge the potential effects of climate change on the ecosystem.

Kiyko and Pogrebov 1997 Barents Sea and Kara Sea

Throughout the Barents and Kara Sea

Analyzed grab, trawl, and underwater photographs between 1991-1992 and compared these data with changes over the last 60-70 years presented for the Barents Sea.

Kozlovskiy et al. 2011 Kara Sea Southwestern Kara Sea Compared the structure and distribution of microbenthic communities from 2007 with samples collected between 1927-1945, 1975, and 1993.

Cross and Thomson 1987 and Cross et al. 1987

Baffin Bay Cape Hatt, Baffin Island Examined the effects of an experimental release of oil on Arctic nearshore infauna and epifauna between 1980-1983.

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In the Canadian Arctic, there are numerous benthic studies that document benthic fauna but long-term studies are scarce. Canadian Arctic benthic environments are

understudied and where studies do exist, they are typically baseline studies that

document the biodiversity observed in a given area under study (Carey 1991, Cusson et

al. 2007, Conlan et al. 2008, Piepenburg et al. 2011, Wei et al. 2019). Long-term studies

are expensive and time- consuming to conduct (Wolfe et al. 1987, Simkanin et al. 2005) and accessibility is an ongoing issue in the Canadian Arctic primarily due to sea ice which restricts accessibility for repeated sampling (Carey 1991).

In the absence of systematically collected long-term data, many authors have called for and have begun to use historical sample data to fill knowledge gaps by combining them with contemporary studies (Wolfe et al. 1987, Kiyko and Pogrebov 1997, Cusson et al. 2007, Renaud et al. 2007, Thurstan et al. 2015). In the Canadian Arctic, numerous historical baseline studies on Arctic benthic communities have been conducted (e.g., Ellis 1955, Wacasey et al. 1979, Wacasey et al. 1980, Thomson 1982, Dale et al. 1989, Syvitski et al. 1989, Aitken and Fournier 1993, Clough et al. 1997, Conlan et al. 2008, Brown et al. 2011a, Nephin et al. 2014). These historical studies provide an opportunity to bridge the gap in knowledge of long-term benthic community change through resampling of these historic sample sites. However, only one study by Cusson et al. (2007) has utilized historical benthic sample records to compile a summary of the current state of knowledge related to the biodiversity of benthic assemblages on the Canadian Arctic continental shelf. In their article, these authors highlight the importance of available historical benthic faunal data and call for these data to be

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integrated with modern sampling efforts in order to set a baseline from which patterns of benthic biodiversity can be measured in the Canadian Arctic. More recently,

Archambault et al. (2010) Thurstan et al. (2015), and Wei et al. (2019) all emphasized the importance of establishing baseline biodiversity datasets across Canada’s Arctic with Thurstan et al. (2015) specifically emphasizing the importance of filling gaps in our knowledge of marine systems through the use of historical datasets, further stressing the importance of setting a baseline from which future change can be measured.