Josianne Støttrup

Influence of algal diet on feeding and egg-production of the calanoid copepod Acartia tonsa Dana

Threshold concentration, retention efficiency and egg-production in the calanoid copepod Acartia tonsa Dana were examined using the algal species Isochrysis galbana clone T-iso, Dunalietta tertiolecta Butcher, Rhodomonas baltica Karsten, Ditylum brightwellii Grunow and Thalassiosira weissflogii Grun. Feeding and egg-production in A. tonsa was shown to be influenced by the size, quantity and quality of the food particles. The small I. galbana (4.8 μm) were inefficiently retained by A. tonsa and maximum ingestion rates on this species were first obtained at algal concentrations s> 1 μg C · ml−1. However, the highest maximum rate of egg-production was obtained when feeding on this algal species with gross efficiencies of 22 and 38% in terms of carbon and nitrogen, respectively. Egg-production in A. tonsa ceased entirely within 4 days of feeding on a sole diet of D. tertiolecta. D. tertiolecta is similar in size to R. baltica but contained only trace amounts of fatty acids higher than C-18 fatty acids. The diatoms D. brightwellii and T. fluviatilis were retained with maximal efficiency but daily egg-production and gross growth efficiency was lower for these species than for I. galbana and R. baltica.

The importance of dietary HUFAs for fecundity and HUFA content in the harpacticoid, Tisbe holothuriae Humes

Abstract Fatty acid distribution was investigated in adult and naupliar Tisbe holothuriae, reared on 3 different diets with n−3 HUFA contents constituting 0.1, 1.5 and and 12.8% DW, respectively. Whereas certain characteristic differences in the fatty acid profiles of the 3 diets used clearly were reflected in the copepods, the long-chain n−3 HUFAs 20:5 n−3 and 22:6 n−3 were present in consistently high amounts. When reared on a diet with negligible contents of n−3 HUFAs, but high in 18:3n−3, T. holothuriae appeared to be able to synthesize these fatty acids at significant rates. Also, the reproductive performance of T. holothuriae on the 3 diets was studied. Of the two microalgal diets studied, the one with the high n−3 HUFA content resulted in considerably higher sustained naupliar productivity during the first 15 days of the production period of the cultures. However, no difference in brood size (first two broods) was found.

Integrated coastal zone management.

Chapter 1: State of Fear or State of Oblivion? What coastal zones are telling us about global change and why we need integrated coastal and ocean management on a global scale. Section 1: Coastal habitats. Chapter 2: The challenge of establishing sustainable utilization of our coastal resources. Chapter 3: Evaluating the geomorphologic stability of an estuarine sandy beach. Chapter 4: Macro-algae habitat as fish nursery: evaluation of function as predation refuge. Chapter 5: Predictive probability modelling of marine habitats - a case study from the West coast of Norway. Section 2: Impacts on coastal systems. Chapter 6: EU Indicators to monitor the progress in ICZM. Chapter 7: The response of hyperbenthos and infauna to hypoxia in fjords along the Skagerrak: Estimating loss of biodiversity due to eutrophication. Chapter 8: Environmental characterisation in the Augusta harbour (Sicily, Italy) using benthic foraminifera: the effects of human impact on benthic environment. Chapter 9: Eco-friendly sustainable shrimp aquaculture in Bangladesh: A way of minimizing coastal degradation. Chapter 10: Bioshields and ecological Restoration in Tsunami-affected areas in India. Chapter 11: The population density and urbanisation at the North-East of Baltic Sea, the time-spatial analysis. Section 3: Integrated Coastal Zone Management (ICZM). Chapter 12: Future challenges in Environmental Policy relative to ICZM (keynote address). Chapter 13: Legal framework for integrated coastal zone management. Chapter 14: Lobster reserves in coastal Skagerrak - An integrated analysis of the implementation process. Chapter 15: Efficiency of Fishing Vessels Affected by a Marine Protected Area - The Case of Small-Scale Trawlers and the Marine Protected Area in Nha Trang Bay, Vietnam. Chapter 16: Socio-economic impacts of sea use change in the German North Sea: A scenario based assessment in the context of regional development. Chapter 17: Integrated Coastal Zone Management (ICZM) in Guyana: development barriers, opportunities and recommendations. Chapter 18: Strategies for the beneficial use of dredged material in Japan. Section 4: Coastal governance. Chapter 19: Management or Governance, Environment or Ecosystem What are the Differences and Does It Matter? (keynote address). Chapter 20: Assisting decision-makers in complex water issues - A case study: Rotterdam Mainport, The Netherlands. Chapter 21: Local coastal zone planning and stakeholder participation in Norway. Chapter 22: The Evolution of Governance Mechanisms for the Eastern Scotian Shelf Integrated Management Initiative. Chapter 23: Climate Change, Coastal Communities and Governance: Developing solutions for change, Australia. Chapter 24: Map of Coastal Zone Vulnerabilities to Wave Actions - Application to Aveiro District (Portugal). Chapter 25: Managing Coastal Vulnerability: New Solutions for Local Government

A Systems Approach Framework for Coastal Zones

This Special Feature Volume examines the potential value of the Systems Approach Framework (SAF) as a methodological framework for the transition to sustainable development in coastal zones. This article provides insight on the Systems Approach, the theory behind it, and how its practical application to coastal zone systems (CZSs) was developed. The SAF is about information for management through a focus on how to generate a higher, dynamic level of information about complex CZSs and how to render this information more useful to end users through a participatory suite of communication methods. The SAF is an open research methodology that investigates the function of systems in order to simulate specific issues or questions concerning their function. The research articles that are included in this Volume demonstrate examples of coupled multidisciplinary methods integrated into SAF simulations appropriate to a selected policy issue and to the social-environmental conditions of each Study Site Application. Their findings are not the result of funded research projects; instead, they are byproducts of pilot applications conducted to develop and improve the SAF methodology. The final article of this Volume synthesizes these results in the context of the SAF as a higher level instrument for integrated coastal zone management.

Rearing of flounder (Platichthys flesus) juveniles in semiextensive systems

A low-technology rearing system was implemented for rearing juvenile flounder for stock enhancement in a Danish fjord, the Limfjord. Each year during 1996–2002, between 13,000 and 153,000 juveniles were reared from the yolk-sac stage until metamorphosis in outdoor ponds relying on phyto- and zooplankton blooms as their main food source. In contrast to other similar systems, the blooms in this system are closely monitored and, to a certain extent, regulated. The zooplankton blooms consisted mainly of calanoid copepods, dominated by the species Temora longicornis and Centropages hamatus. Most juveniles produced (>99.5%) were normally pigmented with average yearly survival rates from hatch to metamorphosis varying from 7 ± 9% to 48 ± 18%, lowest in the first years of production.

A Systems Approach Framework for the Transition to Sustainable Development: Potential Value Based on Coastal Experiments

This article explores the value of the Systems Approach Framework (SAF) as a tool for the transition to sustainable development in coastal zone systems, based on 18 study sites in Europe, where the SAF was developed and tested. The knowledge gained from these experiments concerns the practical aspects of (a) governance in terms of policy effectiveness, (b) sustainability science in terms of applying transdisciplinary science to social-ecological problems, and (c) simulation analysis in terms of quantifying dysfunctions in complex systems. This new knowledge can help broaden our perspectives on how research can be changed to better serve society. The infusion of systems thinking into research and policy making leads to a preference for multi- issue instead of single-issue studies, an expansion from static to dynamic indicators, an understanding of the boundaries between system-dependent and system-independent problems, and the inclusion of non-market evaluations. It also develops a real partnership among research, management, and stakeholders to establish a quantitative basis for collaborative decision making. Furthermore, the article argues that the transition to sustainable development for coastal systems requires consideration of the scale interdependency from individual to global and recognition of the probable global reorganizational emergence of scale- free networks that could cooperate to maximize the integrated sustainability among them.

The effect of carbon dioxide on growth of juvenile Atlantic cod Gadus morhua L.

A trial was undertaken to investigate how exposure to graded hypercapnia affected the growth performance of juvenile (15-80 g) Atlantic cod. Juveniles were grown at 20‰ salinity and 10°C for 55 days under three hypercapnic regimes: low (2±0.9 mg L(-1) CO(2), 0.6mm Hg, 1000 μatm), medium (8±0.5 mg L(-1) CO(2), 2.8mm Hg, 3800 μatm) and high CO(2) exposure (18±0.2 mg L(-1) CO(2), 6.3mm Hg, 8500 μatm). All water quality parameters were within the range of what might normally be considered acceptable for good growth, including the CO(2) levels tested. Weight gain, growth rate and condition factor were substantially reduced with increasing CO(2) dosage. The size-specific growth trajectories of fish reared under the medium and high CO(2) treatments were approximately 2.5 and 7.5 times lower (respectively) than that of fish in the low treatment. Size variance and mortality rate was not significantly different amongst treatments, indicating that there was no differential size mortality due the effects of hypercapnia, and the CO(2) levels tested were within the adaptive capacity of the fish. In addition, an analysis was carried out of the test CO(2) concentrations reported in three other long-term hypercapnia experiments using marine fish species. The test concentrations were recalculated from the reported carbonate chemistry conditions, and indicated that the CO(2) concentration effect threshold may have been overestimated in two of these studies. Our study suggests that juvenile Atlantic cod are more susceptible to the chronic effects of environmental hypercapnia than other marine fish examined to date.

Mussel Production and Water Framework Directive Targets in the Limfjord, Denmark: an Integrated Assessment for Use in System-Based Management

Growth of human activities often conflict with nature conservation requirements and integrated assessments are necessary to build reliable scenarios for management. In the Limfjord, Denmarks largest estuary, nutrient loading reductions are necessary to fulfill EU regulations criteria, such as the Water Framework Directive (WFD). Cuts in nutrient loadings do not necessarily result in corresponding reductions in eutrophication impacts or in improving primary and higher trophic-level production. Similarly, the socioeconomic consequences of a mussel fishery and aquaculture production are complex and hard to predict. This study focuses on the usefulness of a System Approach Framework (SAF) implementation for stakeholder understanding of complex systems and development of sustainable management. Ecological-social-economic (ESE) model simulations clearly demonstrated the potential problems of WFD implementation for mussel fishers and mussel farmers. Simulation of mussel fishery closures resulted in a tenfold increase in the hitherto fishable mussel biomass and a similar decrease in the biomass of shallow-water mussels and medium-sized ones in deep water. A total closure of the mussel fishery could result in an annual profit loss of ~€6.2 million. Scenario simulation of the introduction of one, two, three, and four mussel culture farms of ~19 ha showed that the introduction of line-mussels would decrease the biomass of wild mussels both in shallow and deep waters, affecting the catch and profit of fishers. The SAF, which included consultation with stakeholders at all stages, differs from the traditional public consultation process in that (1) communication was verbal and multilateral, (2) discussion among stakeholders was facilitated, and (3) stakeholder opinions and priorities formed the focus of the ESE assessment.

Diet, Abundance, and Distribution as Indices of Turbot (Psetta maxima L.) Release Habitat Suitability

Selection of a suitable release habitat is critical for stock enhancement. As part of the Danish turbot stock enhancement program, individually tagged, artificially reared juveniles were released into three different habitats. Data from the recaptures in the following year revealed a significant effect of release habitat on turbot growth. This raised the question whether such differences in growth could have been predicted before the release by comparing easily measurable characteristics of wild turbot caught in the different habitats. Three characteristics of wild turbot were examined: the diet, natural abundance, and depth distribution within the habitats. A marked difference was found among habitats in the timing of the diet change from the suboptimal exoskeleton carrying prey items such as crustaceans to fish. The habitat where the wild turbot had the lowest occurrence of fish in their diet was also the habitat with the highest natural abundance of age-0 individuals and the deepest distribution of wild turbot. This was the habitat where released turbot grew more slowly than in the other habitats, which indicate that the diet and depth distribution of wild turbot may provide good indicators for the success of turbot enhancement and restocking.

Rationale for Restocking the Eastern Baltic Cod Stock

The Danish Institute for Fisheries Research and Bornholms Salmon Hatchery examined the potential for restocking Baltic cod (Gadus morhua callarias L.) in the eastern Baltic Sea. This cod population has adapted to the unique brackish water conditions where successful spawning depends on regular inflows of oxygenated saltwater from the North Sea. Hydrographical conditions are therefore considered to constitute the principal bottleneck for recruitment of this population. Successful recruitment is also dependent upon food availability and predation pressure from mainly herring (Clupea harengus L.) and sprat (Sprattus sprattus L.). A 2-to 3-month delay in the spawning period compared to 20–30 years ago has altered feeding conditions and predation susceptibility in a way that may have exacerbated the decline in recruitment. Producing and releasing cod larvae during spring would mimic the spawning period recorded in previous times and would coincide with the spring peak in copepod production. An evaluation of 3 different release scenarios showed that a release of 474 million first-feeding larvae over 5 months would enhance the average population of 2-year-olds by 10% and be biologically and economically the most feasible scenario.