By adopting an interdisciplinary concerted approach with three individual projects (IP's), one for each country  (Norway, Portugal, United Kingdom and Irland), we will explore the spatial distribution of intraspecific biodiversity in selected species of bony fish and sharks sampled from the continental slopes and from the Mid-Atlantic Ridge (MAR).

Concerted collection of genetic, phenotypic and oceanographic data will help us unravelling the processes responsible for shaping the patterns of population connectivity in the deep-sea.

The objectives is to identify stocks that will react independently to exploitation, and then provide a platform for evidence-based management strategies, and evaluate the potential for biodiversity loss caused by deep-sea fisheries and other anthropogenic pressures.

DEECON consists of three Individual projects (IP’s) aiming to resolve the objectives of the project. Below is a short introduction to aims and objectives for each of them:

IP-1: “Population structure and interconnectivity in the North Atlantic (NA-DEEP)” contribution to the Collaborating Research Project

Centre for Ecological and Evolutionary Synthesis (CEES) - www.cees.no (Nils Chr. Stenseth) 
Institute of Marine Research (IMR) - www.imr.no (Halvor Knutsen)

The overall aim of the IP 1-project is to characterize population genetic structure within selected commercially important species of deep-sea fishes from the North Atlantic, and to identify the main forces behind such substructuring.

The implications of the findings for fisheries management will be identified and reported to the ICES/NAFO fisheries regulatory authorities for use in management and stock conservation. Data will form an important contribution for the overall project North Atlantic Census of Marine Life Programme (COML), of which MAR-ECO is a component.

Characterize amounts and spatial distributions of genetic variability in three species of deep sea fishes, the black scabbardfish (Aphanopus carbo), the roundnose grenadier (Coryphaenoides rupestris), and the ling (Molva molva), by means of microsatellite DNA-genotyping. The spatial genetic differentiation patterns will be interpreted in light of relevant life-history traits, such as the duration of the juvenile pelagic phases (eggs and larvae), the mobility of adults, and the geographic distribution and spawning preferences of the species.

Specifically, we aim at exploring the mechanisms behind population interconnectivity and determine to what extent gene flow occurs among populations in these species and, if so, whether it occurs primarily as a result of passive larval drift with the ocean currents or by active dispersal of adults. This will be determined by comparing the observed population genetic structure with ocean current patterns and bathymetric data, and by comparing species with different life-history traits. Such comparisons will be done in parallel with the IP2 study to increase the number of species and thus broaden the range of life history traits.

IP-2 “Azorean Deep-sea fisheries, population structure and management (AzorDEEP)” contribution to the Collaborating Research Project

University of the Azores, Department of Oceanography and Fisheries (IMAR/DOP) - www.horta.uac.pt (Sergio Stefanni)

The overall aim of the IP-2 is to characterise population genetic structure within selected species of commercially important species of deep-sea fishes and sharks from the North East Atlantic using Mitochondrial DNA (mtDNA) and genomic sequences. In particular we are aiming to characterize amounts mtDNA and nuclear intron sequence polymorphisms for phylogeographies, phylogenies and historical demographies on selected deep sea fishes, the onion-eye grenadier, Macrourus berglax, the roundnose grenadier, Coryphaenoides rupestris and the orange roughy, Hoplostethus atlanticus, as well as in one deep sea shark, the longnose velvet dogfish (Centroselachus crepidator). The intention is to understand how historical contingencies have shaped species distributions to present-day patterns.
 
We are also aiming to explore genomic DNA to determine if any phenomenon of hybridization is present between the two cryptic species of scabbardfish (Aphanopus carbo and A. intermedius) as recently described in the Azores (Stefanni and Knutsen, 2006). Scabbardfish are becoming more and more popular on European fish markets and special attention needs to be addressed.

Special interest is addressed to the North Atlantic circulation of the water masses as this complex combination of forces might be responsible in shaping genetic structure in marine organisms. Two are the regions that will be studied:

1) a coastal region south of Pico Island in the Azores
2) an open ocean region near a seamount or bank located between the Azores and Madeira archipelagos.

One oceanographic mooring will be deployed on the first site (south of Pico). CTD-measurements will be made and water samples will be collected for chlorophyll a and nutrients analyses in the water column. Synoptic near-surface oceanographic information will be obtained through Ocean Colour (OC), thermal Infrared (IR) and altimetry data, obtained from the “HAZO” High Resolution Picture Transmission (HRPT) satellite receiving station at Faial, Azores, from NASA/GSFC, and also from AVISO/Altimetry data.

In situ and satellite data will be used to study ocean dynamics in the two regions and to infer possible underlying forcing mechanisms (e.g. Azores current/front system, wind, internal waves and mixing, exchange across fronts) responsible for some of the observed population genetic structures among the selected deep-sea commercial species.
 
Under the framework of this project and concurrently with other running projects (IP-1 in particular), a nested numerical ocean (ROMS) model will be set-up for the Subtropical Atlantic with emphasis in water dynamics, and seasonal and intra-annual variability in the Azores region. The model results will be validated with the results obtained by satellite altimetry, SST and OC, as well as with in situ data. Eventually, the model will use data assimilating prognostic mode. The nested model will be linked to the larger scale ROMS model that will be developed in IP-1.
 
Aims for this task are to understand and explore the oceanographic mechanisms behind population interconnectivity and to determine the levels of gene flow among populations in these species. This will be done relating observed spatial genetic structures within species with the results from satellite, in situ and numerical modelling (e.g. ocean circulation and dynamics, sea surface temperature, phytoplankton biomass, water mixing) and with bathymetric data, for species with different life-history traits. Such comparisons will be made in parallel with the IP-1 study to increase the number of species and broaden the molecular approaches.

A parallel line of research will address to cryptic deep-sea species belonging to the families Alepocephalidae and Platytroctidae sampled during the MAR-ECO cruises. Systematists were not able to determine the taxonomic status and we will molecular markers as tool to clarify the taxonomical position of such species giving also a contribution to the “barcoding of marine life”.

IP-3 “Genotypic and phenotypic characterisation of deep-sea fish population structure (GP-DEEP)” contribution to the Collaborating Research Project

University College Dublin (UCD) - www.ucd.ie (Stefano Mariani) 
Fisheries Research Services (FRS) - www.frs-scotland.gov.uk (Francis Neat)

The overall aim of the IP-3 project is to characterize the population genetic structure of two selected commercially important deep-sea fish species from the North Atlantic, using an integration of genotypic and phenotypic approaches. We will then attempt to explain the patterns identified taking into account oceanographical, historical and ecological processes.

We intend to unravel the patterns of population structuring of two bathyal fish species recently become subject to exploitation: the onion-eye grenadier (Macrourus berglax) and the longnose velvet dogfish (Centroselachus crepidator), across continental slopes, seamounts and trenches between the Azores and north-western Norway.

Two independent sets of markers will be employed:  Molecular genetic analysis of microsatellite polymorphisms and otolith trace element composition.

The present task is closely interwoven with IP-1: Otolith microchemistry will be examined also in the black scabbardfish (Aphanopus carbo) and the roundnose grenadier (Coryphaenoides rupestris), which will be genetically analysed by Partner 1 (IMR). This will yield a double phenotypic/genotypic data set for four deep-sea target species (other phenotypic descriptors will be used for C. crepidator, as cartilagenous fish do not possess otoliths).

The differentiation patterns inferred will be interpreted in light of the life-history traits of each species (e.g. duration of pelagic phases, the mobility of adults, habitat preferences, spawning season), as well as comparing spatial population structure with oceanographic models describing ocean current patterns, and with bathymetric data. To our knowledge, this is the first time such an integrated analysis (molecular genetics, otolith microchemistry, oceanographic modelling) is being attempted at such a scale.