CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Responses of H. planatus to environmental stressors of Ushuaia Bay. Laboratory and field experiments.
Autor/es:
COMOGLIO, LAURA INÉS; CAMILIÓN, MARÍA CAROLINA; AMIN, OSCAR ANTONIO
Lugar:
Brasil
Reunión:
Congreso; X Congreso Brasilero de Ecotoxicología; 2008
Institución organizadora:
SETAC Brasil
Resumen:
Halicarcinus planatus (Decapoda, Brachyura) is a crab that inhabits coastal zone of Beagle Channel. Ushuaia Bay received different anthropogenic (domestic effluents) and natural (i.e. defrosting event), which change the natural water condition. The aim of the present study is to evaluate the use of this crab as suitable bioindicator of environmental health. Organisms (CL=8.12±0.64 mm) were collected from the intertidal zone of Bahia Ensenada, (National Park) in September 2007. Three environmental stressors, salinity (25; 30; 35 ups), pH (7.5; 8.5; 9.5) and ammonia (0.3; 3; 30 mgN-NH3) and three “in situ” experiments in zones with different inputs: Industrial Zone; Yacht Club and Encerrada Bay were carried out by 96h, without registered mortalities. Oxygen consumption, ammonia excretion and O:N ratio were choice as response to exposure. Eighty crabs for each laboratory and environment experiments were used. Oxygen consumption and ammonia excretion increased in organisms exposed to 25ups (174.38 µgO2/h/g and 12.80 µgN-NH3/h/g) while O:N ratio was higher in 30ups  (ANOVA,p<0.05). At pH 9.5 higher values of oxygen consumption and ammonia excretion and minor value of O:N were registered (199.45 µgO2/h/g and 27.82 µgN-NH3/h/g). Ammonia exposure showed that organisms exposed at 3 mgN-NH3 increase both oxygen consumption (232 µgO2/h/g) and ammonia excretion (26.29 µgN-NH3/h/g), showing the minor value of O:N. In field experiments all treatments showed significant higher values of oxygen consumption respect the initial control group (mean value 193.64±3.21 µgO2/h/g) (ANOVA,p<0.05). Organisms exposed to IZ have presented the higher ammonia excretion values, followed by YC (24.87±5.13 and 16.57±1.27 µgN-NH3/h/g respectively). No changes respect to initial measure, were observed in EB-trial. ON ratio resulted higher in EB meanwhile minor in ZI and homogeneous in YC. In spite of H. planatus respond to specific as well to complex environmental stressors, further studies are necessary to achieve information to evaluate the potential of use it as bioindicator.