Mapping Biological Resources in the Coastal Zone: An Evaluation of Methods in a Pioneering Study from Norway

For many years, the planning and management of terrestrial areas has been supported by a detailed knowledge of the distribution of habitats and their associated species. However, the detailed mapping of biological resources in extent coastal areas, such as the Norwegian coastal zone, is unrealistic due to its enormous coastline. Here, we present a useful and feasible approach and a set of simple, cost-effective methods which are suitable for providing a broad-scale overview of marine habitats and fish resources. This approach was developed in conjunction with a pioneer study conducted along the southern coast of the Skagerrak, where we combined knowledge gathered from local fishermen with scientific knowledge of important species and nature types to establish a coastal sea mapping program. GIS modeling tools were used in both the mapping program and to integrate local and scientific knowledge into digital maps made available to local area management. This multi-faceted approach, which combines local knowledge and scientific methods, provides valuable information with respect to marine biodiversity, and has been used extensively by local environmental management.     

Adaptive capacity determinants in developed states: examples from the Nordic countries and Russia

Adaptive capacity in a community context has so far mainly been studied in developing countries as well as indigenous communities in the industrialised world. This article adds to that literature through reviewing studies undertaken in the Nordic countries and Russia, highlighting the ways in which general determinants of adaptive capacity play out in Northern, industrialised contexts. The paper illustrates that the determinants of adaptive capacity in industrialised states exhibit systematic differences from mixed subsistence-cash based communities such as those found in Arctic Canada. We discuss in particular the importance of economic resources in a market-based system, technological competition, and infrastructure, in determining adaptive capacity of natural resource-dependent communities in the Nordic countries and Russia. The paper also illustrates differences in adaptive capacity within the case study region, including between peripheral and central locations with regard to economic resources and diversification possibilities, and between Nordic and Russian cases with regard to infrastructure and technology access. The findings indicate that understanding of determinants of adaptive capacity in resource-dependent communities would benefit from both further contextualisation and broad comparison, across different types of political and administrative systems.     

Incubation start and egg size in relation to body reserves in the common eider

Avian incubation is often initiated before all eggs are laid. In altricial birds this has been proposed to facilitate brood reduction through asynchronous hatching. However, in precocial birds eggs normally hatch synchronously even if incubation has started before all eggs are laid. Patterns of incubation start may be the adaptive trait selected for both in altricial and precocial species. Several hypotheses have been proposed to explain the timing of incubation start in birds. Decreasing egg-size after incubation start may be adaptively related to an early incubation start, either to ensure synchronous hatching or to decrease fitness cost of late hatched eggs. We have measured individual body condition, egg size and start of incubation in common eider Somateria mollissima, a precocial sea-duck which does not feed during the incubation period. Females in poor body condition start to incubate earlier in the laying sequence than those in good body condition. Furthermore females in poor body condition lay smaller final eggs than females in good body condition. The laying of smaller eggs late in the sequence is therefore probably related to energetic or nutritional state. We propose that females in poor body condition start to incubate early to shorten the nest period in order to reduce their mass loss, but at the cost of reduced size and growth of the ducklings from the eggs laid after incubation start. Females in good body condition on the other hand postpone incubation start at the cost of a longer incubation period and a higher mass loss to the benefit of synchronized hatching and a higher survival of ducklings.     

Small-scale genetic structure in a marine population in relation to water circulation and egg characteristics

Until the last decade it was assumed that most marine species have pronounced gene flow over vast areas, largely because of their potential for dispersal during early life stages. However, recent genetic, modeling, and field studies have shown that marine populations may be structured at scales that are inconsistent with extensive dispersal of eggs and larvae. Such findings have stimulated the birth of new studies explaining the mechanisms that promote population structure and isolation in the oceans, in the face of high potential for dispersal. Here we study the vertical and horizontal distribution of cod (Gadus morhua) eggs in relation to small-scale circulation and water column hydrography in a coastal location of southern Norway. Previous studies conducted in this region have shown that cod populations inhabiting fjord locations, which are on average 30 km apart, are genetically differentiated, a remarkable outcome considering that Atlantic cod have pelagic egg stages and long pelagic larval duration. We document that cod eggs are found in greater abundance in shallow water layers, which on average are flowing up the fjord (away from the open ocean), and in the inner portion of the fjord, which is subject to lower current speeds compared to the outer or mouth of the fjord. Eggs were found to be neutrally buoyant at shallow depths, a trait that also favors local retention, given the local circulation. The same patterns held during two environmentally contrasting years. These results strongly suggest that population structure of Atlantic cod is favored and maintained by a balance between water circulation and egg characteristics.