Arctic Yearbook 2015 - Page 178

178 Arctic Yearbook 2015 “weaker-link” public good. In view thereof it is in fact the least effective provider (Burnett 2006; Perrings et al. 2002) that actually determines whether the ecosystem’s overall balance and well-being will not go out of kilter. In other words, the introduction, establishment and magnitude of spread of a new species hinges on those (countries) that exert the least effort to prevent and/or control purposeful or accidental invasions, noting decisions about prevention might differ decidedly between deliberately introduced and accidentally introduced invasive species. Effective control of biological invasions in the multi-state Arctic is a weakest-link public good and a driving force for coordinated proactive action. Climate change has also aided species movements that take on characteristics of invasions. The North East Atlantic mackerel have been moving westward and northward with shifts in oceanic temperatures and related properties, and this has sparked disputes between Iceland and the Faroe Islands on the one hand and Norway and the EU on the other hand. While information on the stock of the mackerel and the ability to estimate the overall quota to maintain a healthy fishery is well understood and widely distributed through the International Council for the Exploration of the Sea (ICES 2013, 2014, 2015), the negotiations for joint quotas covering how the catch should be distributed have been very problematic so far. This is particularly true regarding the newly viable coastal fisheries developing around Iceland where there has been a tremendous increase in stocks in recent years (Ellefsen 2013; Ørebech 2013). The species distribution has changed significantly since the mid-2000s, having spread quite a lot into East Greenlandic and Faroese waters as well, while overall stock size has also increased (Dankel et al. 2015). Those changes in population dynamics have apparently hindered agreements between mackerel fishing countries on the Total Allowable Catch, but both the competitive role of mackerel within the food-web (preying on other species) and the overwhelming dependence on those fisheries urgently call for an effective and optimal management scheme (Ørebech 2013). Human assisted invasive species introductions Directly, the role of industrial development in increasing the probability of successful invasions must be addressed. The burden of costs and the sharing of benefits of such measures are not evenly distributed, and will depend on the policy choices made (including lack of policy or implementation). These policies, for example, might include assignment of liability to sources of invasive species, such as shipping, tourist or fishing vessels that transverse a variety of sensitive ecosystems with their gear, or resource extractors who develop infrastructure that creates substrate and creates increased traffic flows to new