Variation in Serripes groenlandicus (Bivalvia) growth in a
Norwegian high-Arctic fjord: Evidence for local- and
large-scale climatic forcing
William G. Ambrose, Jr.
*†
, Michael L. Carroll
†
, Michael
Greenacre
‡
, Simon R. Thorrold
§
, Kelton W. McMahon
*§
* Bates College, Department of Biology, Lewiston, Maine 04240, USA
†Akvaplan-niva, Polar Environmental Centre, N9296 Tromsø, Norway
‡ Pompeu Fabra University, 08005 Barcelona, Spain
§ Woods Hole Oceanographic Institution, Biology Department MS 50, Woods Hole,
Massachusetts 02543, USA
* Corresponding Author:
W.G. Ambrose, Jr.
Bates College
Department of Biology
Lewiston, Maine 04240, USA
Tel: +1 207 786 6114
Fax: +1 207 786 8334
Email:
wambrose@bates.edu
Key Words: Arctic Climate Regime Index, Serripes groenlandicus, bivalve growth, Arctic,
Svalbard, benthic community, benthos, climate forcing
Running Title: Bivalve growth and Arctic climate
Received:
Ambrose et al., Bivalve growth and Arctic climate
Page Page 2 of of 39
Abstract
We examined the growth rate of the circumpolar Greenland Cockle (Serripes
groenlandicus) over a period of 20 years (1983-2002) from Rijpfjord, a high-Arctic fjord
in northeast Svalbard (80º 10´ N, 22° 15´ E ). This period encompassed different phases of
large-scale climatic oscillations with accompanying variations in local physical variables
(temperature, atmospheric pressure, precipitation, sea ice cover), allowing us to analyze the
linkage between growth rate, climatic oscillations, and their local physical and biological
manifestations. Standard Growth Index (SGI), an ontogenetically-adjusted measure of
annual growth, ranged from a low of 0.27 in 2002 up to 2.46 in 1996. Interannual
variation in growth corresponded to the Arctic Climate Regime Index (ACRI), with high
growth rates during the positive ACRI phase characterized by cyclonic ocean circulation
and a warmer and wetter climate. Growth rates were influenced by local manifestations of
the ACRI: positively correlated with precipitation and to a lesser extent negatively
correlated with atmospheric pressure. A multiple regression model explains 65% of the
variability in growth rate by the ACRI and precipitation at the nearest meteorological
station. There were, however, complexities in the relationship between growth and
physical variables, including an apparent 1-year lag between physical forcing changes and
biological response. Also, when the last 4 years of poor growth are excluded, there is a
very strong negative correlation with ice cover on a pan-arctic scale. Our results suggest
that bivalves, as sentinels of climate change on multi-decadal scales, are sensitive to
environmental variations associated with large-scale changes in climate, but that the effects
will be determined by changes in environmental parameters regulating marine production
and food availability on a local scale.
Ambrose et al., Bivalve growth and Arctic climate
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Introduction
The Arctic climate has changed dramatically in the last several decades (Maxwell,
1997; Overpeck et al., 1997, Johannessen et al., 2003, 2004; AICA 2004). The average
annual air temperature has increased by 1º to 4º C in the last half century (AICA 2004),
and this has been accompanied by changes in terrestrial and marine ecosystems (Oechel &
Vorulitis, 1997; Serreze et al., 2000; Morison et al., 2000). Effects of persistent climate
change on Arctic marine ecosystems are largely undetermined, but changes that occur in
response to decadal-scale climate oscillations may provide insight into longer term effects
of more persistent climate change.
Several large-scale climate oscillations have been shown to influence marine systems
(see Allan et al., 1996; Ottersen et al., 2001; Walther et al., 2002; Stenseth et al., 2003 for
reviews). Linkages between the two climate oscillations with nodes centered in the Arctic,
the Arctic Oscillation (AO) and the Arctic Climate Regime Index (ACRI), and the marine
ecosystem, however, have not been demonstrated. Both indices reflect differences in wind-
driven motion in the central Arctic alternating between two phases, an anticyclonic
circulation regime (ACCR) and a cyclonic circulation regime (CCR). The climate regimes
manifest as physical variables in the Arctic; ACCR is characterized by a cold and dry high-
Arctic atmosphere and a colder and saltier polar ocean (low AO and negative ACRI),
whereas the cyclonic regime is characterized by a warm and wet atmosphere and a warm
and fresh polar ocean (high AO, positive ACRI). Climatic conditions associated with both
the AO and ACRI may affect marine ecosystems as has been demonstrated for the North
Atlantic Oscillation (Ottersen et al. 2001).
Ambrose et al., Bivalve growth and Arctic climate
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Seafloor communities may be the best location to examine the impact of Arctic
climate oscillations, and by extension the potential effects of climate change on the Arctic
ecosystem. There is often a close relationship between water column and benthic
processes (Grebmeier et al., 1988; Ambrose & Renaud, 1995; Piepenburg et al., 1997;
Wollenburg & Kuhnt, 2000; Dunton et al. 2005), and therefore long lived, sessile benthic
organisms, may be more appropriate monitors of climate change (e.g. Kröncke et al., 1998,
2001; Dunton et al. 2005) than the more transient pelagic system. Additionally, benthic
communities are key components in the carbon cycle on Arctic shelves (Grebmeier et al.,
1989, Stein & Macdonald, 2004; Grant et al., 2002; Clough et al., 2005) and food for
higher trophic levels (e.g. bottom feeding fish, mammals, and birds (Dayton, 1990)).
Consequently, changes to the benthos may have profound effects on carbon cycling,
trophic structure, and food web dynamics on Arctic shelves.
Bivalves comprise a significant proportion of the benthic biomass of Arctic shelves
(Zenkevitch, 1963; McDonald et al., 1981; Feder et al., 1994; Gulliksen et al., 1985;
Grebmeier et al., 1988; Dayton, 1990). The shells of most bivalves exhibit periodic
banding, or growth lines (Rhodes & Penella, 1970; Clark, 1974; Rhoads & Lutz, 1980),
that have proved valuable in developing a history of environmental change in marine
systems (Andrews, 1972; Hudson et al., 1976; Jones, 1981; Jones et al., 1989; Witbaard,
1996; Witbaard et al., 1997, 1999; Tallqvist & Sundet, 2000; Schöne 2003; Müeller-Lupp
& Bauch 2005). Temperature and food are the two main factors influencing bivalve growth
(Buekema et al., 1985; Beukema & Cadée, 1991; Jones et al., 1989; Lewis & Cerrato,
1997; Dekker & Beukema, 1999; Witbaard et al., 1997, 1999; Schöne et al., 2005), and
both are likely to be influenced by climate change in Arctic marine systems (Carroll &
Ambrose et al., Bivalve growth and Arctic climate
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Carroll, 2003). Furthermore, many deep water and high latitude bivalves have life spans of
decades (Tallqvist & Sundet, 2000; Müeller-Lupp et al., 2003; Sejr & Christensen, 2006)
to well over 100 years (Turekian et al., 1975; Thomson et al., 1980; Zolotarev, 1980, Peck
& Bullough, 1993; Witbaard et al., 1999, Sejr et al., 2004). Bivalves can thus serve as
bioproxies by providing uninterrupted records of environmental conditions over decades to
centuries, which is critical in the Arctic given the paucity of long term data on community
structure and dynamics.
We examined interannual variation in growth of the circumpolar Greenland Cockle
(Serripes groenlandicus) from 1983-2002 in a high-Arctic fjord in northeast Svalbard
(Norwegian Arctic) to explore the relationship between benthic communities and
environmental variations associated with decadal climate oscillations in the Arctic.
Variation in bivalve growth associated with changes in environmental conditions that
occur over the course of a decadal-scale oscillation cycle provides insight into the response
of a dominant member of the Arctic benthos to predicted long-term climate change.
Materials and Methods
Study Site
Rijpfjord (80° 10´ N, 22° 15´ E) is located on the north-central shore of
Nordaustlandet (Fig. 1), north and east of Spitsbergen in the Svalbard Archipelago.
Rijpfjord is oriented south-north and opens to a broad shallow shelf of approximately
200m depth extending to the shelf-break of the Polar Basin at roughly 81° N. The bottom
depth averages 200-250m, but an irregular sill crosses the width of the fjord midway
through its length. Shallower depths are dominated by bedrock and stones covered with a
thin layer of mud, while soft sediments predominate deeper sections.
