Reef monitors detect nutrient surge as dry season deepens

The Costa Mar Reef Monitoring Network released data Wednesday from its five permanent observation stations, showing elevated nitrogen and phosphorus concentrations at Punta Verde, Bahía Blanca, and the Mangrove Estuary site. The readings, taken over the past ten days, exceed the network's baseline by up to forty percent. Researchers attribute the surge to a combination of factors: reduced freshwater flow from the hydro reservoirs during the dry season, and increased nutrient runoff from agricultural and residential areas upstream.

The timing coincides with a period when Costa Mar's hydroelectric output has begun to tighten. The Federal Hydro Authority reported last week that reservoir levels have fallen to eighty-three percent of capacity, narrowing the margin for water releases that normally dilute and flush coastal nutrient loads. The dry season typically runs through April, but this year's rainfall deficit began earlier than historical averages.

Marina Flores, director of the Reef Monitoring Network, said the pattern is not unprecedented but warrants close attention. "We see this most years, but the magnitude matters," she said in an interview Tuesday. "When the reservoirs are full, we can manage the balance. When they are tight, the reef absorbs the cost." The network will increase sampling frequency to twice weekly at the three affected stations through the end of November.