Publications

Here you will find publications from DTU Aqua:

Recent publications

2018
  PDF

Spatio-Temporal Patterns in the Coral Reef Communities of the Spermonde Archipelago, 2012–2014, II: Fish Assemblages Display Structured Variation Related to Benthic Condition

Year: 2018

Spatio-Temporal Patterns in the Coral Reef Communities of the Spermonde Archipelago, 2012–2014, II: Fish Assemblages Display Structured Variation Related to Benthic Condition

Plass-Johnson, J. G., Teichberg, M., Bednarz, V. N., Gärdes, A., Heiden, J. P., Lukman, M., Miñarro, S., Kegler, H. F., Weiand, L., Wild, C., Reuter, H. & Ferse, S. C. A. 2018 In : Frontiers in Marine Science. 5

Publication: Research - peer-reviewJournal article – Annual report year: 2018

The Spermonde Archipelago is a complex of ~70 mostly populated islands off Southwest Sulawesi, Indonesia, in the center of the Coral Triangle. The reefs in this area are exposed to a high level of anthropogenic disturbances. Previous studies have shown that variation in the benthos is strongly linked to water quality and distance from the mainland. However, little is known about the fish assemblages of the region and if their community structure also follows a relationship with benthic structure and distance from shore. In this study, we used eight islands of the archipelago, varying in distance from 1 to 55 km relative to the mainland, and 3 years of surveys, to describe benthic and fish assemblages and to examine the spatial and temporal influence of benthic composition on the structure of the fish assemblages. Cluster analysis indicated that distinct groups of fish were associated with distance, while few species were present across the entire range of sites. Relating fish communities to benthic composition using a multivariate generalized linear model confirmed that fish groups relate to structural complexity (rugosity) or differing benthic groups; either algae, reef builders (coral and crustose coralline algae) or invertebrates and rubble. From these relationships we can identify sets of fish species that may be lost given continued degradation of the Spermonde reefs. Lastly, the incorporation of water quality, benthic and fish indices indicates that local coral reefs responded positively after an acute disturbance in 2013 with increases in reef builders and fish diversity over relatively short (1 year) time frames. This study contributes an important, missing component (fish community structure) to the growing literature on the Spermonde Archipelago, a system that features environmental pressures common in the greater Southeast Asian region
Original languageEnglish
JournalFrontiers in Marine Science
Volume5
DOIs
StatePublished - 2018

 

Overarching sustainability objectives overcome incompatible directions in the Common Fisheries Policy

Year: 2018

Overarching sustainability objectives overcome incompatible directions in the Common Fisheries Policy

Goti, L., Fitzpatrick, M., Döring, R., Reid, D. G., Mumford, J. & Rindorf, A. 2018 In : Marine Policy.

Publication: Research - peer-reviewJournal article – Annual report year: 2018

The lack of clarity in the objectives of the Common Fisheries Policy (CFP) must be addressed to create a more efficient balance across diverse ecological, economic and social dimensions. Particularly economic and social objectives present at an overarching level must be made explicit and addressed in lower level management measures, in order to link them to biological objectives and allow policy to build a balance across types of objectives. Selecting clear objectives is essential, particularly for policy impact assessment. The aim of this paper is to demonstrate how more specific high level objectives to managing fisheries can be derived from stakeholders. The paper first reviews the definition of objectives, from a historical and conceptual perspective. Secondly, it discusses the issues of manageability and acceptability, and finally describes an articulation of the high level objectives derived from extensive stakeholder consultations at European and regional level. The results from workshops at the European level to identify objectives were further examined at regional level for the Baltic and North Seas in additional individual consultations. The German case addresses two seas (Baltic and North Seas), has a complex governance structure (due to federalism) and significant roles for the three types of actors (industry, government and environmental NGOs). The analysis suggests that establishing higher level sustainability objectives within the CFP can help diverse interest groups to develop a consensus on management actions to meet complex social goals
Original languageEnglish
JournalMarine Policy
ISSN0308-597X
DOIs
StateAccepted/In press - 2018

 

Ontogenetic development of attack behaviour by turbot larvae when exposed to copepod prey

Year: 2018

Ontogenetic development of attack behaviour by turbot larvae when exposed to copepod prey

Højgaard, J. K., Bruno, E., Støttrup, J. G. & Hansen, B. W. 2018 In : Aquaculture Research.

Publication: Research - peer-reviewJournal article – Annual report year: 2018

Identification of fish larval behavioural traits permitting capture of specific live prey sizes is an important part of optimizing production of marine larvae. We investigated the capture success of turbot larvae (Scophthalmus maximus) at two development stages, 8 and 10 days post‐hatch (DPH), when offered small nauplii (129–202 μm), large nauplii (222–278 μm) and copepodites (342–542 μm), of the calanoid copepod Acartia tonsa. At 8 DPH, turbot larvae had the highest capture success (67%) when offered small nauplii, with a lower capture success of large nauplii (27%) but totally lacked the capabilities to capture copepodites. At DPH 10, the larvae increased the capture success of large nauplii (47%) and achieved a few successful attacks on copepodites. Energetically, large nauplii were the most beneficial at both larval development stages. The swimming kinematics of the period prior to a strike by the larva on the copepod was examined, and the approach pattern of the larva was identified as a controlling mechanism for their strike distance, with the initial approach speed of larva at DPH 10 being significantly less than at DPH 8. In all successful attacks, the strike distance was less than 1.17 mm and was significantly lower than unsuccessful attacks. Since the approach pattern of the larva is linked to its capture success, it could be used as the basis for a feeding scheme based on the swimming performance of individual batches of turbot larvae.
Original languageEnglish
JournalAquaculture Research
ISSN1355-557X
DOIs
StateAccepted/In press - 2018

  PDF

FluoRAS Sensor - Online organic matter for optimising recirculating aquaculture systems

Year: 2018

FluoRAS Sensor - Online organic matter for optimising recirculating aquaculture systems

Hambly, A. & Stedmon, C. 2018 In : Research Ideas and Outcomes. 4, e23957

Publication: Research - peer-reviewJournal article – Annual report year: 2018

FluorRAS will develop a sensor that can save recycled fish farms 30% per year in water and energy consumption for water treatment, as well as optimize nitrogen removal. The sensor will be developed in a partnership between engineers (Krüger A / S) and researchers (DTU), and the product will be made available to the entire sector through Danish Aquaculture. Global aquaculture production is expected to double within the next 15 years. Recycling technology has a great potential for supporting environmentally and economically sustainable production. However, the technology has some challenges in balancing both the maintenance of necessary water quality and water treatment costs. Loss of production due to poor water quality is expensive and can be avoided with correct sensor systems. Accumulation of dissolved organic matter and nutrients in the water reduce the effectiveness of UV treatment, is a source of nutrition for opportunistic pathogens, and reduces the effectiveness of the biofilter's removing ammonia. Modern recycling systems are therefore dependent on a network of online sensors that monitor and respond to changes in water quality, but currently there is a need for a sensor to monitor the accumulation of organic matter. FluoRAS aims to fill this gap in technology by developing an online fluorescence sensor. The sensor is based on non-destructive, online optical technology that does not require chemicals and can run continuously.
Original languageEnglish
Article numbere23957
JournalResearch Ideas and Outcomes
Volume4
ISSN2367-7163
DOIs
StatePublished - 2018

 

Effects of Salinity, Commercial Salts, and Water Type on Cultivation of the Cryptophyte Microalgae Rhodomonas salina and the Calanoid Copepod Acartia tonsa

Year: 2018

Effects of Salinity, Commercial Salts, and Water Type on Cultivation of the Cryptophyte Microalgae Rhodomonas salina and the Calanoid Copepod Acartia tonsa

Jepsen, P. M., Thoisen, C. V., Carron-Cabaret, T., Pinyol Gallemi, A., Nielsen, S. L. & Hansen, B. W. 2018 In : Journal of the World Aquaculture Society.

Publication: Research - peer-reviewJournal article – Annual report year: 2018

Marine aquaculture facilities positioned far from the sea need access to seawater (SW); hence, commercial salts are often the chosen solution. In marine hatcheries, most fish larvae require live feed (zooplankton) that are in turn fed with microalgae. The objective of this research was to investigate the applicability of commercial salts and clarify the potential effects on the cultivation of the microalga Rhodomonas salina and the copepod Acartia tonsa. Three commercial salts were tested, Red Sea Salt (RS), Red Sea – Coral Pro Salt (CP), and Blue Treasure Salt. R. salina was cultured at salinities of 10, 20, and 30 psu resulting in equal growth rates at salinities 20 and 30 in SW and RS mixed with deionized (DI) water. The optimum salinity for R. salina was 29 psu. For A. tonsa eggs, we observed highest hatching success in 30 psu with CP or RS mixed with DI water. The egg hatching success was not affected by salinities 15–40 and optimal hatching was obtained at 27 psu. Results confirm it was possible to use commercial salts for rearing of both R. salina and A. tonsa, widening the application of these species for aquaculture facilities without access to SW.
Original languageEnglish
JournalJournal of the World Aquaculture Society
ISSN0893-8849
DOIs
StateAccepted/In press - 2018


http://www.aqua.dtu.dk/english/publications
26 FEBRUARY 2018