Evaluation of the impacts of land-based contaminants on the benthic faunas of Jakarta Bay, Indonesia

To evaluate the impact of land-based contaminants on benthic faunas, as part of the Land-Ocean Contamination Study (LOCS), a study transect was established in Jakarta Bay, Indonesia during the 1996 southeasterly monsoon. The transect extended 72 km between the city's main port, Tanjung Priok, and the Pilau Seribu Island chain in the Java Sea. The dissolved concentrations of Pb, Cu, Zn, Cr and Ni in seawater, in suspended particulate matter (SPM) and surficial sea bed sediments were measured along the transect at nine sites. In addition, metal concentrations were measured in tissues of the corals Goniopora lobata and Lobophyllia hemprichii at five sites, and of the green mussel, Perna viridis at six sites. An assessment of the impact of contaminants on the faunas was made using a biomarker approach, employing coral community analysis and lysosomal stability with Perna viridis. The results of the study showed two main trends. The distributions of metals dissolved in seawater, in SPM, and in the coral and mussel tissues were similar, and failed to show a consistent graded response from inshore to offshore sites. This suggests that the concentration of metals in waters is the primary route for metal uptake by the coral and mussel tissues. By way of contrast, a clear offshore increase in coral generic diversity, coral cover, coral colony numbers and neutral-red retention time (lysosomal stability) was observed, aug gesting increasing nearshore stress. Whilst the coral community stucture may reflect the seasonally-averaged metal distributions in the bay (shown by the metal content of sea bed sediments which increase shorewards), it is more likely that the coral community structure and lysosomal biomarker are responding principally to other nearshore stresses, such as sediment and nutrient loading of water (sewage) or, more likely, organic contaminants such as oils and other hydrocarbons.Dans le cadre du programme Contamination Continent-Océan (LOCS, Land-Ocean Contamination Study), l'impact des contaminants terrestres sur la faune benthique du golfe de Djakarta (Indonésie) a été évalué en 1996, pendant la mousson du sud-est, sur une radiale de 72 km entre le port principal Tanjung Priok et la chaîne insulaire Pulau Seribu, dans la mer de Java. Les concentrations de Pb, Cu, Zn, Cr et Ni dissous ont été mesurées : 1) dans l'eau de mer, dans les particules en suspension et dans les sédiments superficiels (9 stations) ; 2) dans les tissus des coraux Goniopora lobata et Lobophyllia hemprichii (5 stations) ; 3) dans les tissus de la moule verte Perna viridis (6 stations). L'impact des contaminants sur la faune a été évalué à l'aide d'un marqueur biologique, par analyse de la communauté corallienne et stabilité lysosomiale avec Perna viridis. Deux tendances principales ressortent de cette étude. Les répartitions des métaux dissous dans l'eau de mer, dans les particules en suspension et dans les tissus des coraux et des moules sont similaires, sans variation entre la côte et le large, ce qui suggère que l'eau est la voie d'absorption des métaux par les tissus des coraux et des moules. À l'inverse, une nette augmentation est observée au large dans la diversité des genres coralliens, dans la couverture corallienne, dans le nombre des colonies de coraux et dans le temps de rétention du rouge-neutre (stabilité lysosomiale), ce qui indique un accroissement des contraintes vers la côte. Bien que la structure de la communauté corallienne représente la moyenne saisonnière de la répartition des métaux dans le golfe (illustrée par la teneur en métal des sédiments, croissante vers le rivage), il est probable que la structure de la communauté corallienne et le biomarqueur lysosomial répondent surtout à d'autres contraintes côtières, comme la charge en sédiments et en nutriments (égouts) ou, plus probablement, en contaminants organiques tels que le pétrole et les autres hydrocarbures

Monsoonal alternation of a mixed and a layered structure in the phytoplankton of the euphotic zone of the banda sea (Indonesia):A mathematical analysis of algal pigment fingerprints

The chlorophyll a concentration of the upper 25 m of the euphotic zone of the Banda Sea was 5 times higher in August 1984, in the upwelling season during the southeast monsoon, than in February 1985, during the northwest monsoon when a deep chlorophyll maximum layer was presented at 40–80 m. Similarity between stations was calculated by means of a cluster analysis of the concentrations of 4 different chlorophylls and 6 carotenoids. High similarity over large areas, one to the west and one to the east of the Banda Arc, is evidence of the importance of large-scale phenomena influencing the phytoplankton during the monsoons. All samples taken in the deep chlorophyll maximum layer during the northwest monsoon were clustered as a separate group. Multiple regression analysis of chlorophyll a and the four most important accessory pigments suggests that in August 1984 (upwelling season) the fucoxanthin-containing group (mainly diatoms) contributed 50% to the chlorophyll a in the euphotic zone; green algae and Prymnesiophyceae contributed each 20%, Cyanobacteria only 9%. In February 1985, during the downwelling season, pico- and nanoplankton containing 19'-hexanoyloxyfucoxanthin (Prymnesiophyceae) and zeaxanthin (Cyanobacteria) each contributed 40% of total chlorophyll a, both near the surface and in the deep chlorophyll maximum layer; 19'-butanoyloxyfucoxanthin (a marker of certain Prymnesiophyceae and Chrysophyceae) was only present at depth. On the assumption that Chl. b is a pigment confined to green algae, this group contributed 14% of the Chl. a in the deep maximum. Other green-algal pigments were, however, scarce at depth (lutein, violaxanthin), which suggests presence of Prochlorophyta. Shifts in pigment ratios (zeaxanthin : Chl. a; Chl. b : Chl. a), probably related to light adaptation, hinder the use of algal pigment fingerprints for estimating quantitative composition of natural phytoplankton; indeed, differences between samples in pigment signature can have both a floristic and an ecophysiological background. Statistical analysis of pigment fingerprints may further be complicated due to presence of intermediates of pigment synthesis and breakdown, and poor taxon specificity of fucoxanthins and possibly even of Chl. b and zeaxanthin