Both the Stenella and the Ribeira Brava had to stay in the marina today due to the wind and swell caused by the Atlantic hurricane Ophelia out at sea today. The storm formed southwest of the Azores on Wednesday and is the 10th named cyclone of the 2017 hurricane season. While cetaceans are generally minimally affected by such weather phenomena, it is worth reflecting on the implications of this tempest.
Ophelia is the first storm to reach category 3 so far east, with hurricane Frances being the previous record-holder in 1980. The storm is expected to hit Scotland and Ireland today with winds reaching velocities of over 150km/h, causing both countries to go on lockdown, bracing themselves for extensive property damage and fooding. Research has shown that hurricane frequency and strength are closely correlated with the warming surface waters of the Atlantic which should us to inevitably reflect on the consequences of climate change on life on earth. The large oceans of the planet are highly responsible for the regulation of climate so the predicted warming of surface waters worldwide by 4°C and the associated weather extremes are sure to have detrimental effects not only for people but also for marine life.
Storms in autumn generally help generate the mixing of the water layers that are typically stratified by temperature and salinity with warmer lighter surface water is separated by colder, saltier deep water by the thermocline. A hurricane can cause an upwelling of colder, deeper waters reducing the temperature of surface waters. Besides natural changes in the chemistry and physics of our oceans, several marine species also have a hard time surviving the harsh conditions. Planktonic creatures, that cannot actively swim against the current such as several cnidarian species including the Portugese Man O’ War, will be washed ashore in coastal areas. Younger turtles surfacing to breathe and increase their body temperature will have trouble due to large swell and wind. Although most nekton, particularly cetaceans, are very resistent to such cyclones and even enjoy surfing the high storm waves, many vulnerable individuals like young calves or sick animals may perish if conditions are too harsh. Coral reefs on the west of the Atlantic also suffered severe mechanical damage through the wave activity of the previous 2017 hurricanes.
Ironically, Ophelia is also the name of a central female character who tragically drowns at the finale of the Shakespearean play Hamlet. For us this storm can be a stark reminder of the fragility of our ecosystems and the responsibility we have towards ourselves and the life in our oceans.
by Paula Thake