No abstract

Summary: Coral bleaching events due to elevated temperatures are increasing in both frequency and magnitude worldwide. Mass bleaching was recorded at five sites in the northern Persian Gulf during August and September 2012. Based on available seawater temperature data from field, satellite and previous studies, we suggest that the coral bleaching threshold temperature in the northern Persian Gulf is between 33.5 and 34°C, which is about 1.5 to 2.5°C lower than that in the southern part. To assess the bleaching effects, coral genera counted during 60-minute dives were categorized into four groups including healthy, slightly bleached (<50% bleached tissue), mostly bleached (>50% bleached tissue) and fully bleached colonies. The anomalously high sea surface temperature resulted in massive coral bleaching (~84% coral colonies affected). Acropora spp. colonies, which are known as the most vulnerable corals to thermal stress, were less affected by the bleaching than massive corals, such as Porites, which are among the most thermo-tolerant corals. Turbid waters, suggested as coral refugia against global warming, did not protect corals in this study since most affected corals were found in the most turbid waters. The 2012 bleaching in the northern Persian Gulf was relatively strong from the viewpoint of coral bleaching severity. Longterm monitoring is needed to understand the actual consequences of the bleaching event on the coral reefs and communities.Keywords: coral bleaching; thermal threshold; Iranian islands; Persian Gulf. Evento de blanqueamiento masivo en la zona norte del Gofo Pérsico, 2012Resumen: Los eventos de blanqueamiento de corales están aumentando en frecuencia y magnitud debido al aumento de la temperatura en los océanos. En este trabajo se describe un evento de blanqueamiento masivo observado en seis localidades del norte del Golfo Pérsico entre Agosto y Septiembre de 2012. Los datos de temperatura disponibles, medidas in situ y observaciones de satélites de la temperatura de la superficie del mar, sugieren que la temperatura umbral que desencadena el blanqueo de coral en el norte del Golfo Pérsico corresponde a una temperatura de entre 33,5-34°C que es una temperatura entre 1.5 a 2.5°C inferior a la observada en las zonas más meridionales del Golfo Persico (35-36°C). Para la evaluación de los efectos de blanqueo sobre las comunidades de coral, se realizaron transectos de 60 minutos entre 0 y 6 m de profundidad. Durante las inmersiones cada colonia de coral se identificó a nivel de género y su estado se asignó a una de las siguientes categorías: no afectada, ligeramente afectada (<50% del tejido blanqueado), severamente afectada (>50% del tejido blanqueado) y colonias totalmente afectadas (100% del tejido blanqueado). El análisis de los datos de temperatura permitió identificar una anomalía térmica durante el periodo de blanqueamiento que afectó a un 84% de las colonias censadas. Contrariamente a otros eventos de blanqueamiento analizados, las colonias de Acropora spp., que se encuentran entre las espe...

No abstract

No abstract

Serum biochemical values can be used for monitoring any change in the fish physiological condition and water quality. The aim of this paper was to determine plasma sugar, triglycerides, cholesterol, iron, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) levels of Liza klunzingeri from the Persian Gulf. Blood sample was collected from the caudal vessel with syringes coated with sodium heparin. Biochemical values were: sugar 110.37 ± 28.46 mg/di, triglycerides 96.82 ± 23.40 mg/di and cholesterol 177.28 ± 40.75 mg/di, iron 104.74 ± 19.08 mg/di, ALP 117.62 ± 34.49 u/l and LDH 1613.00 ± 345.34 u/l. A significant positive correlation (P<0.01) was found between triglycerides and sugar. Triglycerides had a significant and positive relationship with cholesterol (P<0.01). ALP also had a significant and positive relationship with sugar (P<0.01) and triglycerides (P<0.05). LDH correlated positively with sugar, cholesterol, triglycerides (P<0.01) and ALP (P<0.05). The results revealed reverse correlation between iron and cholesterol, sugar, triglycerides, ALP, and LDH (P<0.01). This study contributes to the referential biochemical values of the L. klunzingeri. In further studies, the established reference ranges might be useful for the health assessment of this species.