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Greenpeace activists target destructive fishing in Indian Ocean - in pictures.

Greenpeace activists target destructive fishing in Indian Ocean - in pictures.

Can a tourist ban save DiCAPRIO's coral paradise from destruction?

With Chapala's destructive landfall in Yemen just a couple of days in the past, a second tropical cyclone, Megh, has just formed in the Arabian Sea. This one is not forecast to become anywhere near as intense as Chapala did-though we know intensity forecasts can be wrong, as they were at early stages for both Chapala and Patricia.

Tropical shallow-water habitats represent the marine environments with the greatest biodiversity; however, these habitats are the most vulnerable to climate warming. Corals, seagrasses, and macroalgae play a crucial role in the structure, functions, and processes of the coastal ecosystems. Understanding their growth and physiological responses to elevated temperature and interspecific sensitivity is a necessary step to predict the fate of future coastal community. Six species representatives, including Pocillopora acuta, Porites lutea, Halophila ovalis, Thalassia hemprichii, Padina boryana, and Ulva intestinalis, collected from Phuket, Thailand, were subjected to stress manipulation for 5 days. Corals were tested at 27, 29.5, 32, and 34.5°C, while seagrasses and macroalgae were tested at 27, 32, 37, and 42°C. After the stress period, the species were allowed to recover for 5 days at 27°C for corals and 32°C for seagrasses and macroalgae. Non-destructive evaluation of photosynthetic parameters (Fv/Fm, Fv/F0, ϕPSII and rapid light curves) was carried out on days 0, 3, 5, 6, 8, and 10. Chlorophyll contents and growth rates were quantified at the end of stress, and recovery periods. An integrated biomarker response (IBR) approach was adopted to integrate the candidate responses (Fv/Fm, chlorophyll content, and growth rate) and quantify the overall temperature effects. Elevated temperatures were found to affect photosynthesis, chlorophyll content, and growth rates of all species. Lethal effects were detected at 34.5°C in corals, whereas adverse but recoverable effects were detected at 32°C. Seagrasses and macroalgae displayed a rapid decline in photosynthesis and lethal effects at 42°C. In some species, sublethal stress manifested as slower growth and lower chlorophyll content at 37°C, while photosynthesis remained unaffected. Among all, T. hemprichii displayed the highest thermotolerance. IBR provided evidence that elevated temperature affected the overall perf

Tropical cyclones can cause severe destruction of coral reefs with ecological consequences for reef fish communities. Ocean warming is predicted to shorten the return interval for strong tropical cyclones. Understanding the consequences of cyclone impacts on coral reefs is critical to inform local-scale management to support reef resilience and the livelihood security of small-scale fishing communities. Here, we present the first analysis of a tropical cyclone disturbance on coral reefs in Madagascar. We investigate the impact of Cyclone Haruna (category 3 Saffir-Simpson scale) in February 2013 on coral communities, both adults and recruits, and explore the relationship between the severity of cyclone impact with cyclone parameters (wind speed, duration of storm impact and distance from cyclone track) and environmental variables (reef type and reef depth). We use survey data collected as part of a long-term citizen science monitoring programme at 21 coral reef sites between 2012 and 2015 in the Velondriake Locally Managed Marine Area along Madagascar's southwest coast. Coral cover declined at 19 sites, however damage was spatially heterogeneous ranging from a decrease in coral cover of 1.4% to 45.8%. We found the severity of cyclone damage related to: distance from the cyclone track, duration of cyclone impact and reef depth. The taxonomic and morphological composition of coral communities was significantly different after the cyclone. Notably, there was a decrease in the dominance of branching morphologies, and an increase in the relative abundance of encrusting and massive morphologies. Two years after Cyclone Haruna, mean coral cover had increased and the density of coral recruits increased to above pre-cyclone levels indicating the potential recovery of coral populations. However, recovery to pre-disturbance community composition will likely be hindered by the increasing occurrence of acute and chronic disturbance events.

Read Blast fishing turning Tanzania's waters into 'killing fields' latest on ITV News.

Read Blast fishing turning Tanzania's waters into 'killing fields' latest on ITV News.

Off Tanzania, in one of the world's richest seas, why is the catch getting smaller?