A new approach for assessing cold-water coral growthin situusing fluorescent calcein staining

Abstract

-Research on the biology and ecology of cold-water corals (CWCs) is still in its infancy. The growth patterns of CWCs in their natural environments are poorly known. Growth rate investigations on these deep-sea reef builder species are needed to predict recovery times following damage to their ecosystems. This study investigates a new approach for analysing CWC growth rate, suitable for in situ application. Lophelia pertusa and Madrepora oculata (Scleractinian) were collected from the Lacaze-Duthiers canyon in the northwestern Mediterranean Sea (520 m depth), marked and then either redeployed in situ for 6 months, or maintained in aquaria for growth rate comparison at a constant temperature of 13• C, corresponding to their habitat conditions. Two different types of staining (calcein and manganese) and three different exposure times (30, 60 and 240 min) were tested. The results show that calcein offers rapid incorporation and easy detection, making it particularly suitable for skeletal growth rate investigations compared with other chemical staining. In situ linear polyp growth rates of 7.5 ± 1.2 mm y −1 and 3.5 ± 2.1 mm y −1 were measured in new polyps of L. pertusa and M. oculata, respectively. Those values were significantly higher in young polyps than in older ones, where they decreased to 1.3 ± 1.5 mm y −1 and 1.2 ± 1.2 mm y −1 . Beyond the study of coral reef growth processes, this approach offers a methodological basis for habitat quality assessment which could be used in the management of deep-sea marine protected areas (MPA).

In situ growth of deep-sea octocorals after the Deepwater Horizon oil spill

“…with previous findings for several coral species, where "young" branches had higher rates of extension than older branches for a few years following their formation (Lasker et al, 2003;Lartaud et al, 2012). Moreover, branches that produce side branches (generally classified as "Mother branches") tended to grow faster than branches that do not ramify ("Daughter"), especially during the year preceding the formation of a new branch (Lasker et al, 2003).…”

Enhanced Growth Rates of the Mediterranean Mussel in a Coastal Lagoon Driven by Groundwater Inflow

“…New specimens were collected on 27 June 2017 at Font Dame sites but not at Font Estramar sites. Shell length of each individual was measured and specimens were immersed in a calcein solution of 150 mg/L for 1 h. The fluorescent marker calcein is incorporated into growing calcium carbonate structures (Moran, 2000), and used for identification and measurement of growth of various calcifying species (Mahé et al, 2010;Lartaud et al, 2013;Nedoncelle et al, 2013). Sodium bicarbonate (105 g) was added to the solution to adjust the pH to 8.2 and to enhance the solubility of calcein.…”

Optimal bioeconomic management of changing marine resources

“…Recovery from harvest disturbance may take a long time-hundreds of years for deep water corals, which grow on the order of a few millimeters per year (Lartaud et al, 2012)-or a short time-for habitats which are not damaged by fishing, such as long-line fished systems or those with muddy substrates. Additionally, colonization rates can vary widely in marine metacommunities and may depend upon oceanographic features, the distribution of habitat, and species' attributes.…”