A review of selected indicators of particle, nutrient and metal inputs in coral reef lagoon systems

Abstract

This review presents environmental and biological indicators of the impact of three major categories of inputs in coral reef lagoons i.e. particles, nutrients and metals. Information was synthesized to extract well established indicators together with some interesting new concepts currently under development, and to provide the reader with an assessment of their respective advantages and drawbacks. The paper has been organized according to the capacity of three categories of indicators to respond either in a specific or a non specific way to a given source of input. The first section focuses on abiotic indicators which main interest is to respond instantaneously and in a truly specific way to a given source of input. The second and third sections present informations on bioindicators either at the sub-individual level or at the individual to community level, indicator specificity generally decreasing as a direct function of biological or ecological complexity. This review showed that even though significant work has already been done on coral reef ecosystems, much more scientific studies are still needed to answer the growing local demands for simple and truly validated tools to be used in environmental surveys. It is further stressed that, due to the biological and environmental diversity of coral reef lagoons, a preliminary step of on-site validation must be considered as an absolute prerequisite when indicators are planned to be used in the frame of a local environmental monitoring programme.

Environmental impacts of dredging and other sediment disturbances on corals: A review

“…To prevent coral mortality, there is clearly a need for reliable sublethal coral health indicators as early warning for stress but the science for this is still in its infancy (Jameson et al, 1998;Vargas-Angel et al, 2006;Cooper and Fabricius, 2007;Cooper et al, 2009). Such bio-indicators, some of which can show remarkable temporal dynamics in response to variations in water quality , require on-site validation before use in monitoring programs (Fichez et al, 2005).…”

Nutrient status in coral reefs of the Îles Eparses (Scattered Islands): comparison to nearby reefs subject to higher anthropogenic influences (Mozambique Channel and Mascarenes, Indian Ocean)

“…St Leu and St Pierre: REU03, REU06 and REU08) and are impacted by anthropogenic inputs. Several previous reports also highlighted such anthropogenic pollution, particularly near St Gilles (Cuet et al 1988, Cuet 1989, Cuet 1994, Chazotte et al 2002, Fichez et al 2005. Marine embayments such as Port Mathurin and Anse aux Anglais in Rodrigues are also, but to a lesser extent, NO3 enriched, possibly from the mineralization of sewage.…”

“…But anthropogenic pressure induces dramatic changes in these environments (e.g. Richmond 1993, Dubinsky and Stambler 1996, Edinger et al 1998, Knowlton 2001, Saffache 2002, Bellwood et al 2004, Downs et al 2005, Fichez et al 2005. For example, an excess of inorganic nutrients due to domestic sewage release proved to be related to lagoon eutrophication and the proliferation of macroalgae (Hallock and Schlager 1986, Mohammed and Mgaya 2001, Lapointe et al 2005.…”

“…Buchleim 1998, Fichez et al 2005, Lapointe et al 2005. Cuet et al (1988), Cuet (1994) and Vacelet et al (1999), among others, pointed out these excesses in nutrients in Réunion and Mayotte respectively.…”

Dynamics of Suspended Sediments during a Dry Season and Their Consequences on Metal Transportation in a Coral Reef Lagoon Impacted by Mining Activities, New Caledonia

“…This has led to the mobilization and transport of approximately 300 million m 3 of soil material (laterites). Opencast Ni mines have enhanced soil erosion and transportation of sediments and metals into the lagoon [19,[24][25][26][27] with several consequences on the lagoonal ecosystems, including increased sedimentation rates; decreased light penetration and dissolved oxygen levels; and an increased metal contamination in the food web which may affect humans [23,28,29]. The Ni mining industry has flourished for over 25 years, and New Caledonia will remain one of the major worldwide Ni producers for the foreseeable future, with global Ni reserves estimated at around 20-25% [30].…”