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: Over the past decade large carbonate mound structures, situated in several provinces along the European continental margin have been discovered in 600 to 1200 m water depths. These structures appear as single, conical or ridge-like features, which are often colonised by a deep-water coral ecosystem. Cold-water corals Lophelia pertusa and Madrepora oculata dominate the coral community. Associated sessile and vagile fauna, like sponges, soft corals, bivalves, gastrodpods, crinoids, brachiopods, and fish make these bioherms as diverse as their tropical counterparts. The objective of this study is to reconstruct past environmental settings locked in the sediments of a carbonate mound in the northern Porcupine Seabight, west off Ireland. Detailed investigations were concentrated on seven 3.5 to 6 m long sediment cores, retrieved from Propeller Mound and its closer vicinity. This mound is a ~150 m high structure within the Hovland Mound province, a cluster of several sea-floor protruding carbonate mounds. A first detailed analysis on benthic foraminiferal assemblages in the vicinity of a carbonate mound was performed on two sediment cores, one located on top of the mound and a second one from an off-mound position further north as control site. The off-mound samples reveal two different assemblages: (1) an Interglacial group dominated by infaunal species reflecting present-day environmental and oceanographic conditions with high nutrient flux to the sea-floor and low sediment accumulation under a strong hydrodynamic regime, and (2) a Glacial group, dominated by cassidulinid species, which describe an influence of polar conditions with low nutrient supply and cold intermediate waters. A single species, Elphidium excavatum, dominates the lower core section and is described here as a species displaced from shallow shelf areas. This removal of sediments from the shelf is related to a first advance of the Irish Ice Sheet onto the Irish Mainland shelf, inducing high sedimentation rates of ~28 cm/kyr with a coeval sea-level drop of ~50 m during Late Marine Isotope Stage (MIS) 3. Due to an incomplete stratigraphic record in the on-mound core, the same species of the off-mound assemblages have been grouped in on-mound samples. The results indicate a dominance of the Interglacial group, whereas the Glacial group is less abundant throughout the entire core. This pattern indicates the lack of glacial time intervals in the on-mound core, which is coherent with stable oxygen isotope data and U/Th dates on coral fragments, presenting only interglacial/-stadial values and ages. A third assemblage is abundant in samples of the on-mound core showing elevated epibenthic species not occurring in offmound samples or only to a minor degree. This Mound group shows a great affinity to strong currents, high nutrient availability and is supposed to indicate Mediterranean Outflow Water in the northern Porcupine Seabight, as well as a higher coral cover on Propeller Mound in an earlier interglacial period. A Late Pleistocene decline in mound growth for Propeller Mound is suggested by a decrease of the Mound group towards the Holocene, which might face its complete burial in the future as this already happened to the buried mounds of the Magellan Mound province further north. Detailed information on off-mound sediment structures and contents from visual core description and the interpretation of Computer Tomographic images were used to evaluate sedimentary processes in glacial and interglacial periods. The sediments portray the depositional history of the past ~31 kyr BP, mainly controlled by sea-level fluctuations and the climate regime with the advance and retreat of the Irish Ice Sheet onto the Irish Mainland Shelf. A first advance of glaciers is indicated by a turbiditic release slightly older than 31 kyr BP, coherent with Heinrich event 3. During MIS 3 and MIS 2 shelf erosion prevailed with abundant gravity flows and turbidity currents. A change from glaciomarine to hemipelagic contourite sedimentation during the onset of the Holocene indicates the establishment of the strong, present-day hydrodynamic regime at intermediate depths. A general decrease in sediment accumulation with decreasing distance towards Propeller Mound was discovered throughout the entire core sections. This suggests that currents (turbidity currents, gravity flows, bottom currents) have had a strong impact on sediment accumulation at the mound base for the past ~31 kyr BP. Finally, the reconstructed environmental setting deduced from sedimentary and micropaleontological analyses portrays the boundary conditions of the habitable range for the cold-water coral Lophelia pertusa. The growth of this ecosystem occurs during interglacial and interstadial periods, whereas a glacial retreat of corals is documented in the absence of glacial sediments in the onmound core. These conclusions are summarised in a model – the Mound Factory – which efficiently accounts for the moundd development covering the period of the Northern Hemisphere Glaciation (past 3.1–2.5 Ma).

Description: The Joint Global Ocean Flux Study (JGOFS) has completed a decade of intensive process and time-series studies on the regional and temporal dynamics of biogeochemical processes in five diverse ocean basins. Its field program also included a global survey of dissolved inorganic carbon (DIC) in the ocean, including estimates of the exchange of carbon dioxide (CO2) between the ocean and the atmosphere, in cooperation with the World Ocean Circulation Experiment (WOCE). This report describes the principal achievements of JGOFS in ocean observations, technology development and modelling. The study has produced a comprehensive and high-quality database of measurements of ocean biogeochemical properties. Data on temporal and spatial changes in primary production and CO2 exchange, the dynamics of of marine food webs, and the availability of micronutrients have yielded new insights into what governs ocean productivity, carbon cycling and export into the deep ocean, the set of processes collectively known as the "biological pump." With large-scale, high-quality data sets for the partial pressure of CO2 in surface waters as well for other DIC parameters in the ocean and trace gases in the atmosphere, reliable estimates, maps and simulations of air-sea gas flux, anthropogenic carbon and inorganic carbon export are now available. JGOFS scientists have also obtained new insights into the export flux of particulate and dissolved organic carbon (POC and DOG), the variations that occur in the ratio of elements in organic matter, and the utilization and remineralization of organic matter as it falls through the ocean interior to the sediments. JGOFS scientists have amassed long-term data on temporal variability in the exchange of CO2 between the ocean and atmosphere, ecosystem dynamics, and carbon export in the oligotrophic subtropical gyres. They have documented strong links between these variables and large-scale climate patterns such as the El Nino-Southern Oscillation (ENSO) or the North Atlantic Oscillation (NAO). An increase in the abundance of organisms that fix free nitrogen (N-2) and a shift in nutrient limitation from nitrogen to phosphorus in the subtropical North Pacific provide evidence of the effects of a decade of strong El Ninos on ecosystem structure and nutrient dynamics. High-quality data sets, including ocean-color observations from satellites, have helped modellers make great strides in their ability to simulate the biogeochemical and physical constraints on the ocean carbon cycle and to extend their results from the local to the regional and global scales. Ocean carbon-cycle models, when coupled to atmospheric and terrestrial models, will make it possible in the future to predict ways in which land and ocean ecosystems might respond to changes in climate.

Description: Annual catches of Todarodes pacificus in Japan have gradually increased since the late 1980s. Paralarval abundances have also been higher since the late 1980s compared to the late 1970s and mid-1980s. Here is proposed a possible scenario for the recent stock increase based on changing environmental conditions. Based on trends in annual variations in stock and in larval abundances, catches are reviewed and potential spawning areas inferred, assuming that egg masses and hatchlings occur over the continental shelf at temperatures between 15 and 23°C. Changes are then inferred in the spawning areas during 1984–1995, based on GIS data. Since the late 1980s, the autumn and winter spawning areas in the Tsushima Strait and near the Goto Islands appear to have overlapped, and winter spawning sites seem to have expanded over the continental shelf and slope in the East China Sea.

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: A colony of Humboldt penguins Spheniscus humboldti in central Chile was monitored from August 1995 to July 2000 to determine patterns of breeding and colony attendance and how these were affected by climatic (rainfall) and oceanographic (El Niño) factors. Nests were periodically checked for contents and roosting birds were counted from vantage points. Two main breeding events were observed: between August and January (spring event) and between April and June (autumn event). Whereas the spring event regularly produced offspring, the autumn event was systematically affected by rains, causing considerable nest desertion. Adults were present in the colony from August to May, abandoning the colony during winter after the nests were flooded. Juveniles occurred only between November and March. Adults moulted mainly in February, while juveniles moulted in January. During the 1997/98 El Niño episode, the number of breeding pairs was 55 to 85% lower than the mean, the onset of nesting was delayed, and abnormally heavy rainfall flooded nests. While the number of breeding pairs was significantly related to sea surface temperature anomalies (SSTA), breeding success was not. The attendance of adults and juveniles at the colony during El Niño was 25 and 73% lower, respectively, than the mean attendance. This 2-peak breeding strategy of Humboldt penguins appears to have evolved in response to the more favourable oceanographic and climatic conditions of Perú, where breeding is continuous and not interrupted by rains. Although less productive, the species probably maintains its autumnal breeding in central Chile because this provides additional offspring to supplement those regularly produced during the spring event.

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.