Increase understanding of the structure and function of Arctic marine ecosystems and their role in the climate system and advance predictive capabilities
In the changing Arctic, improved understanding of marine ecosystem structure and function offers many benefits and is needed to address several policy drivers. For example, improved ecosystem understanding increases certainty for decision makers charged with environmental stewardship (Stewardship). Understanding also advances current predictive modeling capabilities, which better inform management actions and local communities charged with protecting Arctic marine species and their availability for subsistence hunters (Stewardship, Well-being). Arctic marine ecosystems appear to be in rapid transition due to the dramatic thinning and loss of sea ice over several decades (Stroeve et al. 2012; Post et al. 2013; Renner et al. 2014; Grebmeier and Maslowski 2014). Understanding these changes and their role in the climate system is crucial to improve the understanding of the Arctic marine ecosystems role as a component of planet Earth (Arctic-Global Systems), and cooperation between marine ecosystems researchers and numerous potential collaborators, including northern residents and industry participants, who have particular Local and Indigenous Knowledge of the ecosystems.
Changes in location and timing of seasonal sea ice can have profound and varied effects on pelagic and benthic production, a result of adjusting the transfer of energy from primary producers at the sea surface to the benthos (Bluhm and Gradinger 2008; Moore and Stabeno 2015). A broad ecosystem shift from a benthic- to a pelagic-dominated Arctic marine ecosystem is anticipated at all trophic levels (Grebmeieretal. 2012; Mooreetal. 2014), ultimately impacting human communities (Huntington 2009). Marine ecosystems shifts have already begun in the Arctic with observed changes in species distributions of invertebrates (Richman and Lovvorn 2003), fish (Rand and Logerwell 2011), and mammals (Clarke et al. 2013), as well as changes in the size and growth rates of individual animals (von Biela et al. 2011) and the potential for increased gene flow among and between species (Kelly et al.2010).
The loss of sea ice affects the ability of ice-dependent marine mammals to rest, forage, reproduce, and rear young on ice (Laidre et al. 2015, and references therein) and will change their availability to subsistence hunters. Walrus herds hauled out on land in 7 of the last 9 years, i.e., 2007 to 2015 (C. Jay, personal communication) when the ice edge receded beyond the continental shelf during the autumn ice-minimum (Jay et al. 2012). These events have considerable consequences for population trajectory stemming from increased mortality risks on land (Fay and Kelly 1980; Udevitz et al. 2013). Reduced sea ice has also been associated with limited foraging, declining body condition, and reduced reproduction of polar bears in the southern Beaufort Sea (Rode et al. 2014), as well as impacts to polar bears’ major prey—ringed seals—which are threatened by diminishing sea ice (Kelly et al. 2010; Sundqvist et al. 2012; Iacozza and Ferguson 2014).
Impacts of sea ice loss on whales and ice-dependent seals are less clear (Moore and Huntington 2008; Silber et al. 2016), as are the effects of these changes on Indigenous communities that depend on predictable access to such species (Metcalf and Robards 2008).
Feedback processes (e.g., bio-physical relationships) play a fundamental role in the functioning of Arctic ecosystems. Many of these processes are nonlinear in nature, making it difficult to conceptualize or quantify them and therefore to contrast their impact against other feedbacks (Wiese et al. 2013).
Some biotic responses will be difficult to link to physical influences as Arctic food webs are characterized by slow turnover times. Nonetheless, large responses are anticipated given the lower resilience and greater sensitivity to perturbations of Arctic ecosystems—as compared with subarctic (Whitehouse et al. 2014).
The following Research Objectives summarize the next steps while aiming to integrate environmental information through interdisciplinary research and state-of-the-science modeling approaches.
Interagency collaborations are required to address the marine ecosystem Objectives as several agencies have complementary and overlapping jurisdictions and knowledge in the marine realm.
The work focuses on the following objectives