• European Marine Science

The link between anthropogenic nutrient loads and the magnitude and extent of diatom and Phaeocystis colony blooms in the Southern Bight of the North Sea was explored with the complex ecosystem model MIRO. The model was adapted for resolving the changing nutrient loads, the complex biology of the bloom species and the tight coupling between the benthic and pelagic compartments that characterise this shallow coastal shelf sea ecosystem. State variables included the main inorganic nutrients (nitrate [NO3], ammonium [NH 4], phosphate [PO4] and dissolved silica [DSi]), 3 groups of phytoplankton with different trophic fates (diatoms, nanophytoflagellates and Phaeocystis colonies), 2 zooplankton groups (copepods and microzooplankton), bacteria, and 5 classes of detrital organic matter with different biodegradability. The capability of the MIRO model to properly simulate the observed SW-NE gradient in nutrient enrichment and the seasonal cycle of inorganic and organic C and nutrients, phytoplankton, bacteria and zooplankton in the eastern English Channel and Southern Bight of the North Sea is demonstrated by running the model for the period from 1989 to 1999. The MIRO code was implemented in a simplified multi-box representation of the hydrodynamic regime. These model runs give the first general view of the seasonal dynamics of Phaeocystis colony blooms and nutrient cycling within the domain. C, N and P budget calculations show that (1) the coastal ecosystem has a low nutrient retention and elimination capacity, (2) trophic efficiency of the planktonic system is low, and (3) both are modulated by meteorological forcing.

Ce document est réalisé dans le cadre du projet « Système d’Informations Halieutiques » (SIH) de l’Ifremer, qui constitue le réseau d’observation des ressources halieutiques et des usages associés. Ce projet s’inscrit dans la mission de service d’intérêt public de l’Ifremer consistant à « connaître, évaluer et mettre en valeur les ressources des océans et permettre leur exploitation durable ». Outre la collecte des données pertinentes permettant l’analyse du secteur des pêches, le SIH a en charge l’élaboration d’indicateurs sur les flottilles de pêche et leur restitution sous forme de synthèses aux différents acteurs de la filière pêche et du grand public.

Heute leben 5,5 Mrd. Menschen auf der Welt, im Jahr 1800 waren es erst 1 Mrd. Die durchschnittliche Kindersterblichkeit ist von 129 im Jahr 1955 auf heute 58 pro 1.000 Lebendgeburten gesunken (UNDP, 1997). 1850 lag die mittlere Lebenserwartung in Europa noch unter 50% der heutigen (Deutsche Stiftung Weltbevolkerung, 1998).

It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Workshop funding was granted to M.T., A.M.M.S., and C.M.D. by the UWA Oceans Institute, the Australian Institute of Marine Science, and the Office of Sponsored Research at King Abdullah University of Science and Technology (KAUST). Hays, Graeme C. et al. Peer reviewed

Background: To understand how local ecological knowledge changes and adapts, here in the case of the recent introduction of plant species, we report the knowledge and perceptions of the Ndjuka (Maroon) of French Guiana concerning two tree species, Acacia mangium and niaouli(Melaleuca quinquenervia), which are categorized as “invasive alien plants” in the savannas of their territory. Methods: To this end, semi-structured interviews were conducted between April and July 2022, using a pre-designed questionnaire, plant samples and photographs. The uses, local ecological knowledge, and representations of these species were surveyed among populations of Maroon origin in western French Guiana. All responses to closed questions collected during the field survey were compiled into an Excel spreadsheet in order to perform quantitative analyses, including the calculation of use reports (URs). Results: It appears that the local populations have integrated these two plant species, which are named, used and even traded, into their knowledge systems. On the other hand, neither foreignness nor invasiveness seem to be relevant concepts in the perspective of the informants. The usefulness of these plants is the determining factor of their integration into the Ndjuka medicinal flora, thus resulting in the adaptation of their local ecological knowledge. Conclusion: In addition to highlighting the need for the integration of the discourse of local stakeholders into the management of "invasive alien species”, this study also allows us to observe the forms of adaptation that are set in motion by the arrival of a new species, particularly within populations that are themselves the result of recent migrations. Our results furthermore indicate that such adaptations of local ecological knowledge can occur very quickly.

The ‘temperate’ reef coral Coscinaraea marshae Wells, 1962, is reported from Siberut Island (West Sumatra, Indonesia), a near-equatorial locality, 3375 km away from its northernmost range limit in Western Australia, where it is considered a high-latitude endemic. This tropical record suggests that the latitudinal distributions of poorly recorded reef corals may not yet be fully understood, which might be relevant in the light of progressing seawater warming.

1Associational resistance is a grazing avoidance mechanism resulting from herbivores being less inclined to eat palatable plant species when these species grow in association with unpalatable species. Such facilitative interactions between plant species may have important consequences for patterns of relative abundance and reproduction in plant communities.2We studied the relationship between abundance and flowering success of palatable species and the cover of three unpalatable species (Senecio jacobaea, Iris pseudacorus and Lysimachia vulgaris) in a grassland where moderately intense grazing (0.17–0.42 grazers ha-1) had been ongoing for 3 years. Plots were selected so that there were no systematic differences in microenvironmental conditions associated with the level of cover of unpalatable species.3Several palatable species had a higher frequency, cover and/or flowering success when they grew in the neighbourhood of an unpalatable species.4Several species (both palatable and unpalatable) were significantly taller in the vicinity of a large unpalatable species, probably due to the combined effects of grazing avoidance and increased light competition.5These facilitative effects, however, have not yet resulted in a higher local species richness or plant community evenness. It is nevertheless likely that more pronounced effects will be seen if grazing is continued, because facilitative interactions between plant species induced by grazing have already led to a shift in patterns of abundance and flowering success.

Les systèmes d'informations géographiques (SIG) permettent de regrouper des données spatialisées de natures diverses (bases données, résultats de modèles ...). Le recoupement de ces données permet de créer des indices de productivité. Geographical information systems collect and integrate geographically referenced data of diverse nature (database, model results, etc.). Comparing information from different sources can help formulate productivity indexes.