Description: Commercially exploited stocks that have experienced declines in population abundance have responded by altering life history traits of growth and maturation. Cod is not only becoming mature at an earlier age but also, the majority of the stock comprises fishes with no previous spawning experience. Actual fisheries management does not take in account qualitative differences within the spawning stock. If the stock responds to continued exploitation by shifting maturity to an earlier stage, fish will spawn at smaller sizes. They will produce smaller eggs, and consequently small and less viable larvae, so that the contribution to the spawning stock biomass will be less than expected. There are many advantages for delaying maturation: Larger and heavier fish will be better conditioned for spawning, have higher fecundity and larger eggs that are more viable. Harvesting at delayed recruitment enables the stock to maintain a larger SSB with an expanded age structure while supporting a sustainable fishery.

Description: The present study aimed to know the influence of five phytoplankton species on the feeding behavior, reproduction and survival of the copepod A. tonsa. Biochemical parameters (total lipid, carbohydrate and protein) were measured to know the possible nutritional value of the diet. The species were offered to A tonsa as single and mixed diet. The species used were the flagellates C. acantha and R. baltica, the potentially toxic dinoflagellates A. tamarense and P. lima and the diatom S. costatum. Protein (55-69%) was the major biochemical components per cell volume, following for carbohydrate (17-31%) and lipid (13-18%). The concentration of the biochemical components measured per cell volume influenced the hatching success and survival of the adults. The hatching success was correlated with the egg production and ingestion rate of the copepod and survival of the early stages. No correlation was found between egg production and the biochemical concentration per cell volume. The biochemical components per cell volume showed a high interspecific difference between the species and seemed to better explain part of the nutritional value of the phytoplankton, as the concentrations per dry weight and volume medium. The copepod A tonsa had a selective feeding behavior feeding preferable on S. costatum and R. baltica in the mixed food. The ingestion rate of the specie C. acantha was reduced into the mixed food. The size range of the species offered to A. tonsa did not influence its ingestion rate.The flagellates R. baltica and C. acantha and the mixed food provided the best effects on the reproduction and survival of A. tonsa. The best results among the single foods treatments were found with the alga, with the higher lipid content (R. baltica and C. acantha). The dinoflagellates P. lima all showed eggs production and good hatching but, the survival of adults and early stages was affected. S. costatum prevented egg production. The survival and reproduction of A. tonsa fed on A. tamarense was reduced and comparable to the control (without food). In spite of, no influence was seen when S. costatum, P. lima and A. tamarense were offered mixed with the two flagellates. The mixed food was the best food. This result could demonstrate that the negative effect of these species on the reproduction and survival of A. tonsa was due their insufficient biochemical content as the presence of toxin. A good food muss proved not only a good egg production and hatching success, but a high the survival of the first stages, guaranteed the survival of the organism in the environment. The negative effect of the dinoflagellates on the survival of the early stages of the copepod indicated that these species were a bad food for A. tonsa. Therefore, A. tamarense, S. costatum and P. lima were no a good diet as single food to A. tonsa. The best results with the mixed food could be result from an increase on the levels of DHA, provided for R. baltica, and EPA, provided for S. costatum, also as for the increase of protein supplied for C. acantha, major content of protein per cell volume. But for a better understand of the relation of the biochemical contents with survival e reproduction of aquatic animals makes necessary a analysis of vitamins, minerals and of the constitutes of each gross biochemical composition, such as fatty acids, amino acids, sterols, sugars.

Description: Juvenile and adult Loligo opalescens Berry were video taped in Monterey Bay with the remotely operated vehicle (ROV) Ventana,captured with an otter trawl in Santa Monica Bay, California, and adults were taken from the Monterey Bay fishery. Behavioral observations were made over a 13 h period of video sequences. Allometry measurements were made on 157 squids ranging in size from 12 to 151 mm mantle length (ML). In addition to ML we measured the morphometric characters of fin length(FL), fin width (FW), mantle width (MW), eye diameter (ED), head width (HW), funnel aperture diameter(FA), fourth arm length (AL) and tentacle length(TL). Loligo opalescens changes shape with ontogeny due to negative allometric growth of ED, HW, TL, MW, FA and positive allometric growth of AL, FL and fin area. The allometry measurements were used to determine the size of juvenile squids video-taped in open water. A linear regression can predict dorsal ML in mm from a dimensionless ratio of ML upon ED (r2=0.857, P〈0.001). Sizes and velocities of video-taped animals were estimated from 26 video sequences ranging from 〈1.0 to 8 s. The average velocity for squids ranging from 12–116 mm ML was 0.21 m s–1 and the maximum velocity was 1.60 m s–1(116 mm ML). Allometric measurements can provide scale for 2-dimensional images in order to estimate size, velocity and age of animals.

Description: This study is the first detailed assessment of A. palmata populations of the Turks and Caicos Islands. A total of 203 individual colonies and 62 thickets were tagged on five shallow reefs. Depth, percentages of living tissue, recent mortality and old skeleton were estimated. Presence of disease and predatory snails was noted, and disease spread and grazing rates of the snails estimated. Colonies were found in depths of 0.2 - 4 m. Living tissue for individual colonies (75.9% ± 2.2 SE) was significantly greater than for thickets (58.6% ± 3.6) and in both cases exceeded old skeleton (individuals: 22.7% ± 2.1 SE, thickets: 38.0% ± 3.4 SE). Percentage of recent mortality was very low (individuals: 1.3% ± 0.3 SE, thickets: 3.4% ± 0.7%). We found WBD (n = 2), white pox disease a (WPDa) (n = 7) and white pox disease b (WPDb) (n = 14) with greatly varying spreading rates. The WBD infected colonies showed an atypical spread from the top of the branch towards the base. Coralliophila abbreviata and C. caribaea affected 3 .7 54.7% of the populations (grazing rate: 4.29 cm 2 /day/snail ± 1.16 SE). South Caicos’ A. palmata populations are still in good condition, though increasing human disturbances combined with disease and predatory snails may threaten these populations.

Description: The expedition ARK XIX/3 with the German icebreaking RV "Polarstern" was jointly organized between the Alfred Wegener Institute for Polar and Marine Research (AWI) and the Institut Français de Recherche pour l'Exploitation de la mer (IFREMER), the latter providing the unmanned deep-sea submersible "Victor 6000". AWI and IFREMER offered this unique combination of infrastructure in 2003 to European scientists to permit access on advanced technology in marine research to a broader community. Therefore, this cruise was not only a milestone in the Franco-German cooperation but also an important contribution to the European marine research initiatives. All still pictures and videos taken with "Victor 6000" during the expedition "VICTOR IN THE NORTH" are joint property of AWI and IFREMER with copyright by IFREMER. This material can be used for scientific purposes with the indication of IFREMER's copyright. It would be very much appreciated if the joint effort of AWI and IFREMER in organising the cruise ARK XIX/3 would be mentioned in the acknowledgements of any future publication written on the basis of material collected during the expedition. Any commercial or other than scientific use of either pictures or videos collected with "Victor 6000" needs the written formal approval of IFREMER. The entire cruise report is also available in digital format on a CD-ROM attached to this booklet because many of the pictures and graphs are in colour. All hand written dive log files are permanently stored at the AWI. For a certain period of time the cruise diary will be still accessible via the internet at www.polarstern-victor.de.

Description: Das Verhalten sowohl adulter Weibchen als auch juveniler Karettschildkröten (Eretmochelys imbricata) auf See wurde aufgezeichnet und die Tauchgänge in Abhängigkeit von unterschiedlichen extrensischen und intrensischen Bedingungen analysiert. In den zwei Karibischen Untersuchungsgebieten wurden an den freilebenden Karettschildkröten Geräte befestigt, die Wassertemperatur, Lichtintensität, Schwimmgeschwindigkeit, Tiefe, Himmelsrichtung und Lage im Raum in Messintervallen zwischen 0.25 und 30 sek aufzeichneten. Während der Reproduktionsphase führten adulte Weibchen Ruhetauchgänge durch, die unabhängig vom Tagesrhythmus waren. Lediglich kurz vor der Eiablage zeigte sich ein nachtaktiver Rhythmus. Während eines Hurrikans war das Verhalten des betroffenen Weibchens kurzfristig verändert und die Wassertemperatur mittelfristig erniedrigt. Immature Karettschildkröten zeigten einen deutlich tagaktiven Rhythmus mit kürzeren, aktiven Tauchgängen am Tag und langen Ruhetauchgängen in der Nacht. Nach Beendigung der Nistsaison suchten die untersuchten Weibchen Nahrungsgründe in verschiedenen Himmelsrichtungen und Entfernungen zwischen 70 und 360 km auf. Im grundsätzlichen Tauchverhalten adulter Weibchen ausserhalb der Reproduktionsphase wurde Tagaktivität nachgewiesen. Die erhobenen Daten zeigen eine Abhängigkeit der Tauchdauer von der saisonal schwankenden Wassertemperatur und von der Körpermasse des Tieres.

Description: New seismic and geodetic data from Costa Rica provide insight into seismogenic zone processes in Central America, where the Cocos and Caribbean plates converge. Seismic data are from combined land and ocean bottom deployments in the Nicoya peninsula in northern Costa Rica and near the Osa peninsula in southern Costa Rica. In Nicoya, inversion of GPS data suggests two locked patches centered at 14 ± 2 and 39 ± 6 km depth. Interplate microseismicity is concentrated in the more freely slipping intermediate zone, suggesting that small interseismic earthquakes may not accurately outline the updip limit of the seismogenic zone, the rupture zone for future large earthquakes, at least over the short (∼1 year) observation period. We also estimate northwest motion of a coastal “sliver block” at 8 ± 3 mm/yr, probably related to oblique convergence. In the Osa region to the south, convergence is orthogonal to the trench. Cocos-Caribbean relative motion is partitioned here, with ∼8 cm/yr on the Cocos-Panama block boundary (including a component of permanent shortening across the Fila Costeña fold and thrust belt) and ∼1 cm/yr on the Panama block–Caribbean boundary. The GPS data suggest that the Cocos plate–Panama block boundary is completely locked from ∼10–50 km depth. This large locked zone, as well as associated forearc and back-arc deformation, may be related to subduction of the shallow Cocos Ridge and/or younger lithosphere compared to Nicoya, with consequent higher coupling and compressive stress in the direction of plate convergence.