A common garden experiment with larval Northeast Arctic and Norwegian coastal cod cohorts in replicated mesocosms

A replicated mesocosm experiment was carried out to evaluate differential effects of feeding conditions for larval Northeast Arctic (NA) cod and Norwegian coastal (NC) cod. The two populations were (1) reared together with a 6-day older NA cohort (mixed) in high (HC) and low prey concentration (LC; 2000 and 200 prey/L initially), and (2) reared separately in HC treatments (non-mixed) to be able to evaluate both the effect of feeding conditions and possible effects of size interaction within mesocosms. The larvae were fed natural zooplankton, and the two stocks were identified in the mixed mesocosms by otolith marking. NA larvae hatched at a larger size, had higher growth rates, and survived better than NC larvae in both mixed and non-mixed mesocosms in the HC treatment. The second cohort clearly survived better in the non-mixed than in the mixed mesocosms, indicating the presence of an interaction effect before cannibalism could occur. We found a significant higher weight-at-length between NC and NA larvae (<12 mm), which was bigger than the effect difference due to feeding conditions. Furthermore, a positive relation between survival and initial growth within mesocosms was found. We suggest that lower growth at early larval stages was accompanied by lower survival, and suggest that this was further enhanced when larvae interacted with older and larger larvae.     

The tragedy of soft choices: capacity accumulation and lopsided allocation in the Norwegian coastal cod fishery

Following years of reduced cod stocks and the build up of capture capacity in the coastal fleet, the Norwegian government implemented “access closure” and “vessel quotas” at the end of the 1980s, in order to bring capture capacity under control. However, despite these rather powerful policy tools, the capacity of the Norwegian cod fishery continued to increase during the 1990s. This paper outlines the processes that led to this increase in capture capacity and to the accumulation of vessels in the large size segments of the coastal fleet, the exact opposite result of that intended by the introduction of the fisheries policy. We present two main factors to explain these trends: Firstly, the expansion in quota factors due to exchange or renewal of vessels. This provides vessel-owners with more “vessel-meters” which are equivalent to an increased share of total quota under the maximal quota regulations. This situation implies a redistribution of resources from smaller to larger vessels. Secondly, improved efficiency of technology aboard the vessels makes the vessels more efficient as capture machines. The effect of these changes remains hidden as long as the total stock increases, which was the situation from the introduction of the new regime and until the late 1990s. When the stock once again declined, the effect of the capacity build-up was exposed. A decade of soft choices, adjustments, and adaptations has used up the available solutions. New regulations and a new policy are now required.     

Feasibility of ranching coastal cod (Gadus morhua) compared with on-growing, full-cycle farming and fishing

The feasibility of ranching wild cod in ‘herds’ was compared with three other scenarios: on-growing of wild cod in sea cages, full-cycle cod farming with hatchery produced juveniles, and commercial cod fishery. In the calculations it was assumed that an existing fishing company could either fish, ranch or on-grow 200 tons of cod quota to increase the quota yield or sell it to invest in full-cycle farming. The results indicate ranching to be the most profitable, fishing as the second and on-growing as the third, whereas full-cycle farming appears to be unrewarding. The net present value (NPV) of the four scenarios was €754 000, €532 000, €198 000 and €−95 000, respectively. Ranching based on aggregating and growing wild cod in a reserved coastal area with anthropogenic feeding thus has the potential of decreasing the cost of fishing, improving growth rate and enhancing quota yield without the investments required in conventional farming. As cod ranching is in the initial stages of development the risks are higher than in the well established cod fishery.     

Can cod farming affect cod fishing? A system evaluation of sustainability

The cod resources in the Barents Sea constitute the most important fisheries in Norway. In order to reduce resource allocation conflicts among different gear and vessel groups and to ensure profit for all participants throughout the value chain, the sector is thoroughly organized. The institutions established to ensure long-term sustainability, have been developed within the framework of a joint Norwegian–Russian fisheries management regime. However, due to a very high fishing mortality, the cod stock is now under severe pressure. In addition, a major part of the cod fisheries is highly seasonal and unable to be a stable supplier to neither the land-based industry nor demanding international markets. In parallel, cod farming is expected to become a new emerging industry, with potential to copy the success of farmed Atlantic salmon. Many actors within the cod fisheries fear the future competition from the growing cod farming sector. With reference to important attributes that characterize the cod fisheries and cod farming, this paper discusses how a future farming industry may affect the traditional cod fisheries. Moreover, we discuss how the fisheries may be forced to organize in the future to encounter the expected competition from cod farming.     

Cheating about the cod

The Northeast Arctic cod is managed by a total quota shared evenly between Norway and Russia. It appears that Russia has been overfishing its quota by substantial amounts for a number of years, due to insufficient monitoring of fishing vessels. This paper considers what would be the best reply by Norway to given levels of Russian overfishing. It is found that in most cases the best Norwegian reply would be also to overfish its quota. An aggregate biomass model with stochastic growth and recruitment is used to analyze this question, with parameters estimated from 1946 to 2005 data. Recruitment is serially correlated but apparently independent of the spawning stock. A model using the estimated serial correlation in recruitment and a random disturbance is capable of reproducing recruitment patterns similar to the irregular pattern observed since 1946.     

欧式鳕鱼排的研制

以鳕鱼为原料 ,经过鱼糜制作、调味、速冻、切片、浸液、沾粉、二次速冻等工艺研制开发了欧式鳕鱼排。探讨了原、辅料和漂洗条件对产品质量的影响 ,测定了评价产品质量的感官、理化和微生物指标。     

Feedback switching and the evolution of U.S. coastal management

Feedbacks occur when advocates engage to clarify the implementation of a policy innovation such as the requirement that federal activities be consistent with objectives of state coastal management plans. Discrete policy feedbacks include advocacy, litigation, appeals of decisions as well as other activities inserted into policy implementation by interests or government agencies acting in their behalf. Feedback analysis is applied to the time after the passage of the 1972 U.S. Coastal Zone Management Act. Conflicts after passage of the law resulted in a negative feedback in the form of a Supreme Court decision in 1984 and a subsequent positive feedback through the 1990 revision of the law effectively reversing the Court decision. New insights documented here suggest that feedback switching, wherein old disputes are moved to new arenas, provides the greatest opportunity for overcoming negative feedbacks that could diminish or eliminate the policy innovation. Furthermore observing feedbacks through time and across multiple policy spaces as demonstrated here provides a robust interpretation of policy evolution from a new perspective. This analysis demonstrates how feedbacks convert a voluntary state program into one with authority over certain federal actions. These findings will be important for other areas of coastal policy and, more broadly, policy evolution in general.