Mortality of marine invertebrate larvae in mercury, copper, and zinc solutions

Abstract

The times taken to kill 50% of their larvae were determined for some species of bryozoans (Watersipora cucullata (Busk), Bugula neritina L.), tubeworms (Spiuorbis lamellosa Lamarck, Galeolaria caespitosa Lamarck), bivalve molluscs (Mytilus edulis planulatus Lamarck, Crassostrea commercialis Iredale & Roughley), and the brine shrimp (Artemia salina L.). The molar concentrations of mercury (added as mercuric chloride), required to kill 50 % of the larvae of the above species in 2 hr were 5 .O x IO+M, 1 . 0~ 10-GM, 7 . 0~ IO+M, 6 . 0~ 1 0 +~, 6.5 x IO-+M, 9 . 0~ IO-~M, and 9 . 0~ 1 0 -3~, respectively. The pH of these solutions ranged from 7.8 to 8.2. For Watersipora, Bugula, and Spirorbis, mercury was more toxic than copper and copper was more toxic than zinc when the copper and zinc were added as citrates. The following concentrations of copper produced 50% mortality of the larvae in 2 hr over a pH range of 7.0-8.2: Watersipora 9 . 0~1 0 -6~, Bugula 6 . 0~1 0 -5~, Spirorbis 8 . 0~1 0 -~~, Galeolaria 4 . 5 x 1 0 -3~, and Mytilus 3.5 x 10-4~. Comparable data for zinc over a pH range of 7.6-8 .O were: Watersipora 5.0 x 1 0 -4~, Bugula 8.0 x 1 0 -5~, and Spirorbis 7.5 x 1 0 -5~.During experiments with bivalve mollusc larvae in concentrated copper solutions (5.0 x 10-ZM) it was noted that the pH was sufficiently acid (3.5) to dissolve the shells away. The effect of low pH as a mortality factor in such solutions was investigated using Artemia larvae. It was found that the death rate of larvae in copper concentrations of 1 .Ox 10-1 to 4 . 0~ 10-BM, with a pH of 3.2-4.5 was similar to that of larvae in comparable solutions not containing copper, but with a similar pH range. Therefore, the effect of the lowered pH in concentrated copper solutions needs to be taken into account in assessing mortality rates. Of the larvae tested Artemia appeared to have the greatest potential as a test organism for screening potential antifouling compounds.This study was aimed at assessing the suitability of a number of marine invertebrate larvae as test organisms for screening potential antifouling compounds. Bryo-Loans, tubeworms, and bivalve molluscs are important fouling organisms in New South Wales (Allen and Wood 1950; Wisely 1959) and therefore the larvae of two species of each group were included. Barnacles were not included because the settling seasons and identity of the cyprids of species in the area have not yet been studied and consequently tow-netting to obtain identifiable material was not practical. Overseas workers have already studied the reactions of representatives of this group

Effects of dissolved mercury on embryo-genesis, survival, growth and metamorphosis of Crassostrea gigas oyster larvae

“…Valve closure is a well-known protective mechanism against environmental stress in adult molluscs (reviewed by Akberali & Trueman 1985). Rapid shell closure in response to toxics has also been recorded by previous workers for larvae (Wisely & Blick 1967). In the present study, partial and total inhibition of swimming was also observed (Table 2).…”

“…Mercury has been proved to be the most toxic heavy metal for bivalve larvae (Okubo & Okubo 1962, and also for larvae of many other marine invertebrates such as bryozoans, polychaetes, crustaceans and echinoderms (Okubo & Okubo 1962, Wisely & Blick 1967, Connor 1972, Johnson & Gentile 1979, Martin et al 1981. Its high toxicity and bioaccumulation give Hg a well-known ecotoxicological relevance (recently reviewed by ) and, additionally, enables the use of relatively low, environmentally realistic doses, avoiding pH and solubility problems caused by other heavy metals (Wisely & Blick 1967, Hrs-Brenko et al 1977.…”

“…Its high toxicity and bioaccumulation give Hg a well-known ecotoxicological relevance (recently reviewed by ) and, additionally, enables the use of relatively low, environmentally realistic doses, avoiding pH and solubility problems caused by other heavy metals (Wisely & Blick 1967, Hrs-Brenko et al 1977.…”

Toxicity studies and environmental impact assessment

“…For example, it has been demonstrated that low level concentrations of toxicants can affect growth rates and metamorphosis (Bookhout et al, 1972;Bresch and Arendt, 1977;DeCoursey and Vernberg, 1972;Shealy and Sandifer, 1975); regeneration rates (Weis, 1977); respiratory responses (Calabrese et al, 1975; Thurberg and Dawson, 1974, Vernberg et al, 1973Vernberg and Vernberg, 1972); osmoregulatory control (Roesijadi et al, 1976, a,b); and behavior patterns (Barthalmus, 1977;DeCoursey and Vernberg, 1972; Hansen et ah, 1973;Kania and O'Hara, 1974;Vernberg et al, 1973Vernberg et al, , 1974. To complicate the analysis of pollutant effects further it has also been amply demonstrated that larval stages are often more sensitive to a particular toxicant than are adults (DeCoursey and Vernberg, 1972;Rosenberg and Costlow, 1976;Wisely and Blick, 1967) and environmental factors, such as temperature and salinity, can interact to influence toxicity (O'Hara, 1973;Vernberg et al, 1973Vernberg et al, , 1974Vernberg and Vernberg, 1972;Weis, 1977). The substantial documentation from these and other similar studies has made it abundantly clear that sublethal quantities of pollutants can modify the physiological and behavioral functioning of many species of animals.…”

Patterns of higher taxon colonisation and development in sessile marine benthic assemblages at Casey Station, Antarctica, and their use in environmental monitoring

“…The contaminants in Brown Bay are mainly metals from the waste disposal site, which leach into the bay during summer melt and are highly concentrated in sediments of the bay (Stark et al 2003b). Bryozoans, in particular their larval stage, are sensitive to metals (Wisely & Blick 1967, Henry et al 1989, with reduced survivorship of recruits after exposure to dissolved metals (Ng & Keough 2003). Temperate sponges are also sensitive to metals, which can affect their growth, fecundity and survival (Cebrian et al 2003).…”