Larvae have been difficult to study because their small size limits our ability to understand their behavior and the conditions they experience. Questions about larval transport focus largely on (a) where they go [dispersal] and (b) where they come from [connectivity]. Mechanisms of transport have been intensively studied in recent decades. As our ability to identify larval sources develops, the consequences of connectivity are garnering more consideration. Attention to transport and connectivity issues has increased dramatically in the past decade, fueled by changing motivations that now include management of fisheries resources, understanding of the spread of invasive species, conservation through the design of marine reserves, and prediction of climate-change effects. Current progress involves both technological advances and the integration of disciplines and approaches. This review focuses on insights gained from physical modeling, chemical tracking, and genetic approaches. I consider how new findings are motivating paradigm shifts concerning (1) life-history consequences; (2) the openness of marine populations, self-recruitment, and population connectivity; (3) the role of behavior; and (4) the significance of variability in space and time. A challenge for the future will be to integrate methods that address dispersal on short (intragenerational) timescales such as elemental fingerprinting and numerical simulations with those that reflect longer timescales such as gene flow estimates and demographic modeling. Recognition and treatment of the continuum between ecological and evolutionary timescales will be necessary to advance the mechanistic understanding of larval and population dynamics.

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Recent progress in understanding larval dispersal: new directions and digressions

High resolution distribution of trace elements in the calcite shell layer of modern mytilus edulis: environmental and biological controls

https://digital.library.unt.edu/ark:/67531/metadc933571/m2/1/high_res_d/974271.pdf

On mobilization of lead and arsenic in groundwater in response to CO2 leakage from deep geological storage

Experimental studies of impacts of harbour sediments resuspension to marine invertebrates larvae: Bioavailability of Cd, Cu, Pb and Zn and toxicity☆

The distributions of Cd, Pb and Zn in the total soft tissues and total shells of the green-lipped mussel Perna viridis were studied in field collected samples as well as from laboratory experimental samples. The results showed that Cd, Pb and Zn were readily accumulated in the whole shells. In mussels sampled from 12 locations along the west coast of Peninsular Malaysia, the ratios of the shell metals to the soft tissue metals were different at each sampling site. Nevertheless, the Cd and Pb levels in the shells were always higher than those in the soft tissues, while the Zn level was higher in the soft tissues than in the shells. In comparison with soft tissues, the degrees of variability for Pb and Cd concentrations in the shells were lower. The lower degrees of variability and significant (P<0.05) correlation coefficients of Cd and Pb within the shells support the use of the mussel shell as a suitable biomonitoring material for the two metals rather than the soft tissue since this indicated that there is more precision (lower CV) in the determination of metal concentrations in the shell than in the soft tissue. Experimental work showed that the pattern of depuration in the shell was not similar to that of the soft tissue although their patterns of accumulation were similar. This indicated that the depuration of heavy metals in the shell was not affected by the physiological conditions of the mussels. Although Zn could be regulated by the soft tissue, the incorporated Cd, Pb and Zn remained in the shell matrices. The present results support the use of the total shell of P. viridis as a potential biomonitoring material for long-term contamination of Cd, Pb and Zn.

/pdf/can-the-shell-of-the-green-lipped-mussel-perna-viridis-from-1go8k3iwlb.pdf

Can the shell of the green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia be a potential biomonitoring material for Cd, Pb and Zn?

A strong correlation is observed between the lead content of the shell of the bivalve, Mya arenaria, and dissolved Pb in the seawater in which it grows. Three intertidal sites populated with Mya were selected for study and monitored at least once per month for dissolved Pb during 1988 and 1989. Organisms were collected at the end of the growing season of each year and the most recent annual growth increment was analysed for Pb. A comparison of lead concentrations in shells to seasonally averaged dissolved Pb determined at each of these sites yields a linear relationship described by:

Pbshell(nmol g-1) = (9·99 ± 1·18)Pbwater(nmol kg-1)-0·05 r = 0·97

Lead in the shell of Mya is concentrated by a factor of 10000 relative to seawater making it a sensitive indicator for ambient Pb concentrations. The Pb content of shells excavated from middens left by Indians inhabiting the Boston Harbor islands and radio-carbon dated to be 1600 years old, suggest that pre-industrial dissolved Pb concentrations in Boston Harbor were 24 ± 8 pmol kg-1. Present day concentrations are 25-50 times higher.

Leonard C. Pitts

Papers

Lead Deposition in the Shell of the Bivalve, Mya arenaria: an Indicator of Dissolved Lead in Seawater