Toxicity of copper on marine organisms from the Black Sea

Objective: To investigate the effect of copper on Crangon crangon (Linnaeus, 1758) (C. crangon) and Syngnathus acus (Linnaeus, 1758) (S. acus) from Black Sea. Methods: The acute toxicity of copper in water with clean sediment to C. crangon and S. acus from Sinop Peninsula of the Black Sea was evaluated by static 10-day and 21-day bioassays. Results: Mortality of both organisms increased with increase in concentrations of copper. The results showed that S. acus was more sensitive to copper than C. crangon. Conclusions: In the present study, both C. crangon and S. acus have been shown to be a suitable test species to assess heavy metal toxicity using static 21-day and 10-day bioassays.

Toxicity of cadmium on larvae of Palaemon adspersus Rathke, 1837 from the Black Sea

Objective: To evaluate the suitability of Palaemon adspersus (P. adspersus) as a bio-indicator for 4 and 10 days of cadmium toxicity bioassays. Methods: Four and ten days experiments were designed. CdCl2·2?H2O was dissolved in distilled water and a stock solution was made. At 4-day bioassay, the larvae of Baltic prawns were exposed to nominal concentrations of 0, 0.02, 0.05, 0.1, 0.5, 1.0 and 5.0 mg/L of Cd for 4 days. The 4-day LC50 was calculated by the probit analysis. At 10-day bioassay, the concentrations of 0.05, 0.1, 0.5, 1.0, 5.0, 10.0 and 20.0 mg/L were introduced into each of the jars in triplicate treatments and 0 mg/L as control. Each tank containing 20 larvae was exposed to test solutions. Results: Results from probit analysis showed that the 96-h LC50 value was 0.14 mg/L for Cd. The 10 days bioassays were conducted with nominal concentrations of 0, 0.05, 0.1, 0.5, 1.0, 5.0, 10.0 and 20.0 mg/L Cd. Mortality increased in parallel with the increase in concentrations of Cd on Zoea – I stage of P. adspersus and time of exposure. The toxicity rate of the organism is concentration-dependent. All organisms except the control group died at the end of 10 days. Less than 25% of the animals survived at the 5 days of the exposure to concentrations of 0.5 mg/kg Cd or more. Only 20% of the organisms survived at the 7 days of the exposure to concentrations of 0.1 mg/kg Cd or less in seawater with clean sediment. Conclusions: The results showed that Cd was highly toxic to P. adspersus. When the larvae were exposed to concentrations of Cd, they become slightly excited and swam erratically, probably due to stress. However, behavioural and swimming patterns in control groups were normal, and there was not any mortality during the course of the experiment.

Population dynamics of Philocheras trispinosus(Crangonidae)with abundance of other caridean shrimps(Crustacea:Decapoda)caught by beam trawl in the Southern Black Sea,Turkey

Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried out monthly with a beam trawl of 2 m length and 15 mm cod-end mesh size between December 2012 and November 2013.All individuals were sampled between 1 and 40+m water depth from 146 hauls.Results:A total of 550 P.trispinosus,618 Palaemon adspersus,12 Palaemon serratus,11 Philocheras fasciatus and 10 Crangon crangon were sampled during the study period.The crangonid shrimps started appearing during the winter and spring and the number of individuals increased to reach their highest value in mid-winter and mid-spring.The seasonal von Bertalanffy growth parameters for P.trispinosus were estimated as L_(∞)=29.3 mm total length,K=0.860/year,t_(0)=–0.900 year,C=0.180,and t_(s)=0.010.The start of the slow growth period was at the beginning of July(WP=0.510).Ovigerous females appeared in the sampling area between January and April.Size at sexual maturity was estimated as 25.69 mm total length.Conclusions:The results supported the distribution and abundance of caridean shrimp species from the study area and the population dynamics of the most abundant shrimp species,P.trispinosus.The current study can be answered as baseline data prior to management strategies to ensure sustainable conservation of the shrimp species.