Multi-species dynamics above and beneath the sea-surface

It is essential to account for multi-species dynamics if we want to manage marine resources efficiently and sustainably. Multi-species interactions exist both above and beneath the sea-surface, and the fisher's catch and landings decisions link what happens in the market, above the sea-surface, with what happens in the waters below the surface. The research project analyzes the interplay between the behavioral, market, the biological dimensions of the fisheries system and the regulatory system in several ways. First, we undertake a statistical analysis of landing tickets and related vessel-level data. Using these economic data, we can answer a long-standing biological debate of whether climate change or fisheries drive the observed northwards shift in the distribution of the North East Arctic cod's spawning aggregation. We find no evidence for the hypothesis that age truncation caused by high fishing mortalities is the cause for the distribution shift, but rather climate change is the most likely cause. This work has opened new questions, namely how fishers adapt to these changes in the distribution of the fish stock. Do they follow the fish into new areas, or do they lag behind? Second, we focus on the multi-species dynamics beneath the sea-surface and investigate how using economic information would inform biological stock projections and the debate on "balanced harvesting." In particular, we point to the conditions that need to be satisfied for such a radical change in fishing pattern were to be satisfied. First, the underlying fish stock must satisfy a very specific combination of growth and mortality rates that is likely to be found only in very special cases. Second, the cost for catching small fish and plankton must decrease dramatically for this fishing strategy to become viable. Third, consumer preferences must shift from large fish such as cod, salmon, and herring to very small fish and zooplankton for this fishing pattern to contribute to global food security. Third, we use new ways to analyze the interplay between regulations and fishers' incentives, and we uncover people's basic behavioral preferences using economic experiments in which individuals face real trade-offs between monetary payoffs. A main result from this work is that individual preferences such as discount rates and risk aversion affect both compliance decisions and whether to invest in fisheries. In one study, we investigate how the combination of individual characteristics, such as loss aversion and social norms affect the attitude towards violating regulations, for example regarding the landings obligation. In another study, we investigate more carefully the drivers of investment dynamics in either quota or vessel and gear and how they interact with compliance attitudes. Such insights may help designing more effective regulation by recognizing the motivational base of fishers' compliance. We conclude the project by unifying the lessons learned into policy advice. We develop a dynamic bioeconomic model, in which a scientific body provides an optimal TAC given restrictions on (i) transferability between vessel segments and (ii) entrance of new vessels, which reflects the institutional context in Norway. We apply the model to the Northeast Arctic cod fishery, and determine optimal second-best policies and quantify corresponding welfare effects for our case study fishery. Another important policy proposal that comes out of the project is the exploration of an alternative way to measure quotas. By measuring quotas in number of fish instead of weight, as is currently the case in almost all Norwegian fisheries (wrasse is an exception), one could significantly reduce the problem of growth over-fishing. The logic is simple: A fisher that has a quota in weight does not care about the size of the fish caught when filling his quota. A fisher with a number quota, in contrast, has strong incentives to change his fishing pattern (by choosing appropriate gear and locations) in a way that ensures that he mainly catches large fish.

The project funded a postdoc for four years. In addition to training this early-career researcher, the project has allowed the project PIs to further build their research profile and gain experience with new data. The work on the large landings ticket dataset enabled through the project proved valuable. The work with this dataset was e.g. the basis for a high impact publication in Global Change Biology. Also, this work led to the formulation of new research questions that are now being explored in the follow-up project FishTech (#280541). A second dataset the project enabled further study of, was survey data on the compliance attitudes among Norwegian fishers coupled with experimentally elicited economic preferences. The results from this work have also appeared in NOU2019:21. The work in this commission with a Seasurf researcher as member, was one of several places in which Seasurf researchers engaged in productive two-way interactions with policy makers and other stakeholders.

It is essential to account for multi-species dynamics if we want to manage marine resources efficiently and sustainably. To this end, we need to acknowledge that multi-species interactions exist both above and beneath the sea-surface, and that they are linked through fishermen behavior. For example, cod and haddock are both substitutes in the market (above the sea-surface) and competitors beneath the sea surface. Fishermen's catch and landing decisions are the pivotal element of marine socio-ecological systems, as they essentially connect what happens above and below the sea surface. Regulation that ignore those systemic feedbacks will lead to suboptimal, or even undesired, outcomes. We propose a series of work-packages to analyze the interplay between the behavioral, market, and biological dimensions of the fisheries system and the regulations they are embedded in. First, we undertake a statistical analysis of landing tickets and related vessel-level data to describe fishermen behavior and we complement this by a game-theoretical analysis of the underlying incentives. Second, we focus on the multi-species dynamics beneath the sea-surface and investigate how using economic information would inform biological stock projections and the debate on "balanced harvesting." Third, we go beyond standard bio-economic tools to analyze the interplay between regulations and fishermen's incentives with help of evolutionary game-theory, and we uncover fundamental behavioral preferences using economic experiments. Fourth, we develop unified conceptual framework to span WP 1-3 and we forge the learned lessons into policy advice. A unique strength of this proposal is that it combines and integrates state-of-the art biological and economic modeling, statistical investigations and economic experiments. We are a dedicated team of theoretically and empirically minded ecologists and economists that are united by the aim to forward the sustainable management of renewable resources.