The global integrated world ocean assessment: linking observations to science and policy across multiple scales

In 2004, the United Nations (UN) General Assembly approved a Regular Process to report on the environmental, economic and social aspects of the world's ocean. The Regular Process for Global Reporting and Assessment of the State of the Marine Environment, including Socioeconomic Aspects produced the first global integrated assessment of the marine environment in December 2016 (known as the first World Ocean Assessment). The second assessment, to be delivered in December 2020, will build on the baselines included in the first assessment, with a focus on establishing trends in the marine environment with relevance to global reporting needs such as those associated with the UN Sustainable Development Goals. Central to the assessment process and its outputs are two components. First, is the utilization of ocean observation and monitoring outputs and research to temporally assess physical, chemical, biological, social, economic and cultural components of coastal and marine environments to establish their current state, impacts currently affecting coastal and marine environments, responses to those impacts and associated ongoing trends. Second, is the knowledge brokering of ocean observations and associated research to provide key information that can be utilized and applied to address management and policy needs at local, regional and global scales. Through identifying both knowledge gaps and capacity needs, the assessment process also provides direction to policy makers for the future development and deployment of sustained observation systems that are required for enhancing knowledge and supporting national aspirations associated with the sustainable development of coastal and marine ecosystems. Input from the ocean observation community, managers and policy makers is critical for ensuring that the vital information required for supporting the science policy interface objectives of the Regular Process is included in the assessment. This community white paper discusses developments in linking ocean observations and science with policy achieved as part of the assessment process, and those required for providing strategic linkages into the future.Agência financiadora - United Nations Division for Ocean Affairs and the Law of the Seainfo:eu-repo/semantics/publishedVersio

Experimental evaluation of influence of FADs on community structure and fisheries in coastal Kenya

Fish aggregating devices (FADs) have been widely used by commercial fisheries to increase the catchability of pelagic stocks in the open sea. FADs have the potential to enhance nearshore small-scale fisheries where stocks are often overfished. This study examined changes in catch composition, abundance, catch and effort, and aspects of diversity in Kenya's nearshore coastal fisheries after deployment of anchored fish aggregating devices (AFADs). The study combined both fishery independent and dependent methods in assessing changes in fish assemblages post-deployment. Results showed orders of magnitude increase in length, weight, commercial value, and catch per unit effort (CPUE) of landed catch after deployment of FADs suggesting that FADs had a positive effect on the local fishery. Species richness at FAD sites increased post-deployment (n = 281) compared to pre-deployment values (n = 223). Simultaneous use of several complementary structural indices may be required in order to accurately describe and monitor fish assemblages around the FADs. The findings suggest that AFADs are capable of creating both short and long-term impacts on livelihoods, with the potential to deflect pressure on the overfished nearshore fish stocks. However, more research will be needed on redistribution of fish around FADs, design and placement configuration, and site selection amongst others

Patterns of spat settlement recorded for the tropical oyster crassostrea cucullata (born 1778) and the barnacle, balanus amphitrite (darwin 1854) in a mangrove creek

The spatfall patterns of the oyster, Crassostrea cucullata (Born 1778) and the barnacle, Balanus amphitrite (Darwin 1854) on cemented coconut shells were studied in relation to shore levels and monsoon seasons in East Africa. Both oysters and barnacles settled most frequently above the Mean Tide Level (MTL). About 75.6% of the oyster and 96.9% of the barnacles occurred above the MTL. Thus below MTL, the oyster spat had a better niche advantage over the barnacles. However, at the latter levels the oysters faced heavy competition from fouling organisms, which were mostly spirobids, serpulids, bryozoans, hydrozoans and sponges. The spat of both oysters and barnacles showed seasonality in their settlement. About 93.1% of the total oyster spat settlement occurred in the South East Monsoon (SEM) and the number of spat at peak settlement was 12.6 times the total spat settlement in the North East Monsoon (NEM). As regards the barnacles, 86.4% of the total barnacle spat settlement occurred in SEM and the number of spat in the peak settlement was 3.4 times the total settlement in NEM. Oysters and barnacles on the cemented coconut shells had a wider vertical distributional range than those found on mangrove trees. © 1994 Taylor & Francis Group, LLC.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Predatory activity and spatial strategies of Epixanthus dentatus (Decapoda: Oziidae), an ambush predator among the mangroves

The predatory patterns and spatial strategies of Epixanthus dentatus were studied in a mangrove creek on the Kenyan coast, together with laboratory analysis aimed at assessing the natural diet. This xanthoid fed on almost all the slowly moving invertebrates common in the forest and actively preyed at night, using an ambush technique. Epixanthus dentatus is faithful to individual dens among the roots and to well-defined feeding areas within a 3-m radius, which they shared with an average of 2 other individuals. The high density of E. dentatus seemed to affect the behavior of major prey species; various grapsid crab species reduced their climbing activity during the peak activity periods of E. dentatus. The density of E. dentatus among the mangrove roots was determined both by the number of suitable dens, and, more directly, by the density of prey species.Link_to_subscribed_fulltex

Influence of Seasonality and Bathymetry on Assemblage Structure of Decapod Crustaceans in the Malindi-Ungwana Bay, Kenya

Decapod crustaceans support both artisanal and semi-industrial fisheries in the Western Indian Ocean (WIO) region. Despite their commercial value, data on assemblage structure is lacking in most of the WIO region but are important for stock management. This study provides information on seasonal and bathymetric variation in assemblage structure of decapod crustaceans in Malindi-Ungwana Bay, a biodiversity rich ecosystem in Kenya. Samples were collected during the northeast monsoon (NEM) and southeast monsoon (SEM) seasons during a two-week experimental bottom trawling survey in 2011 under the South West Indian Ocean Fisheries Project (SWIOFP). A total of 43 transects covering an estimated area of 546 nm2 were trawled in four depth zones (0-10, 10-20, 20-40 and 40-100 m) for both seasons. Twenty species of decapod crustaceans belonging to 7 families were sampled in both seasons. The species were distributed in the families; Penaeidae, Portunidae, Calappidae, Majidae, Matutidae, Palinuridae and Scyllaridae. The penaeid shrimps had higher relative numerical abundance both in the NEM (89.3%) and SEM (85.3%) seasons. Of the penaeid shrimps, Fenneropenaeus indicus, had the highest relative abundance both in the NEM (58%) and SEM (42%) season. ANOSIM test indicated significant difference in total crustacean abundance (individuals/km2) between the depth zones (R=0.375; P=0.001; considering all seasons) but no significant difference between the seasons (R= -0.031; P=0.602; considering all depths). Simple Correspondence Analyses segregated the population into SEM assemblages dominated by the Penaeidae and a mixed group NEM assemblage. Canonical Correspondence Analysis showed temperature, salinity, Secchi depth and dissolved oxygen to have seasonal influence on the bathymetric distribution of the crustaceans in the bay. The structure of the assemblages seems to be influenced more by depth profiles than by seasonality. It is recommended that variations in bathymetric distribution of the crustaceans be taken into consideration when developing a crustacean fishery management plan for the bay.

Growth and survival of post-larval giant tiger shrimp Penaeus monodon feeding on mangrove leaf litter biofilms

Biofilm associated with decomposing mangrove leaf litter is a food source for shrimp post-larvae (PL). PL of giant tiger shrimp Penaeus monodon foraging on leaf litter of Rhizophora mucronata with developing biofilm at 1, 3, 4, 6, and 8 wk of decomposition were tested for specific growth rate (SGR, %) and percentage survival (SR, %). Biofilm was analyzed for species composition, abundance, and biomass of microalgae and epifauna. Microalgal biomass increased with the progress of litter decomposition. Diatoms, especially Navicula sp. and Nitzschia sp., dominated the first 6 wk of litter decomposition with a percentage cover of 88 and 99% during the third and fourth weeks, respectively. Cyanobacteria dominated in the 8 wk old biofilm with 61% cover. Copepods dominated the epifauna during the first 3 wk of litter decomposition. In the 4 to 5 wk old litter, polychaetes were most abundant whereas nematodes were dominant in litter that had decomposed for 8 wk. PL foraging on 4 wk old litter had a higher SGR (1.6 +/- 0.5%) and SR (39.8 +/- 4.8%) coincident with the maximum abundance of microalgae and epifauna. The study illustrated that nutritionally rich biofilm for PL shrimp is: (1) developed during the fourth week of mangrove leaf litter decomposition and is dominated by diatoms, polychaetes, harpacticoid copepods, and oligochaetes; and (2) limited by the collapse of the epifauna and subsequent colonization by cyanobacteria in mangrove leaf litter decomposed beyond 4 wk

Fatty acid profiling reveals a trophic link between mangrove leaf litter biofilms and the post-larvae of giant tiger shrimp Penaeus monodon

Shrimp ponds integrated with mangroves intercept leaf litter which may contribute to the bioenergetics of shrimps. Since fatty acids (FAs) determine the nutritive value of shrimp food, we analyzed and compared the FA profiles of post-larvae (PL) of Penaeus monodon fed with decomposing litter of Rhizophora mucronata, the associated biofilm, or a nutritionally optimized compound food. Three nutritionally important stages of decomposition (1, 5, and 10 wk) were tested. FA levels of PL at the start of the experiment were used as controls. As litter de composed, saturated FAs decreased, whereas mono unsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) increased. PUFA concentrations were higher in biofilm than in the litter. PL fed with litter and biofilm food had higher MUFAs, arachidonic acid (ARA), and eicosapentaenoic acid (EPA) compared to PL fed with a compound food. However, PL fed with compound food had higher linoleic acid and docosahexaenoic acid (DHA). PL fed with 5 wk decomposed litter and its biofilm had a high concentration of bacterial odd carbon chain FAs. FAs in shrimp tissue reflected the FA profiles of the food sources in all treatments, with biofilm and compound food showing a better match. We conclude that (1) mangrove biofilm is a potential source of essential FAs to PL, especially providing ARA, EPA, and DHA; (2) biofilm on mangrove leaf litter may upgrade the nutritional value of PL for their consumers, including humans; and (3) efforts should be made to promote periphytic biofilms in integrated mangrove-shrimp culture practices

Marching to a different drummer: Crabs synchronize reproduction to a 14-month lunar-tidal cycle

Biological rhythms with lunar components are common in nature. In the sea, the moon's gravitational pull on earth is the principal cause of the tides, which normally reach maximum amplitudes every new and full moon. Many populations synchronize spawning to this time. Some choose either the new or the full moon, implying that moonlight is important; but one lunar phase usually has higher tides than the other, and many species select the phase with the higher tide to improve the offshore transport of their progeny. However, tidal dominance by one lunar phase is not constant; it switches between new and full moon every seven months. We tested the influence of this 14-month "syzygy inequality cycle" (SIC) on lunar synchrony by sampling 11 populations of intertidal crabs at two locations in East Africa for 21 months. Eight populations synchronized larval release with the SIC. Tidal cues were more important than moonlight in entraining the reproductive rhythm, although two populations synchronized spawning to the new moon. SIC synchrony increased with population shore level, because only the higher lunar tide permitted top-shore spawning. Top-shore species therefore have a restricted lunar choice. SIC synchrony could be common, given that it occurs in most marine environments. © 2005 by the Ecological Society of America.Link_to_subscribed_fulltex