Answer:
To test my hypothesis that El Niño is having negative biological effects on the marine environment along the Peruvian coast, I would collect several types of data:
Water temperature data: I would measure the temperature of the water at various locations along the Peruvian coast to determine if there are any changes in temperature that correspond to El Niño events.
Ocean chemistry data: I would measure the pH, salinity, and other chemical parameters of the water to determine if there are any changes in ocean chemistry that correspond to El Niño events.
Marine life data: I would survey the populations of marine organisms along the Peruvian coast to determine if there are any changes in abundance or distribution of species that correspond to El Niño events. This could include fish, crustaceans, and other marine animals.
Plankton data: I would sample and analyze the plankton community along the Peruvian coast to determine if there are any changes in abundance or species composition that correspond to El Niño events.
Remote sensing data: I would use satellite imagery to monitor the changes in sea surface temperature, ocean color, and sea level.
Historical data: I would also examine historical data of previous El Nino events and their impact on the marine environment along the Peruvian coast.
By analyzing these data together, I would be able to determine if there is a correlation between El Niño events and changes in the marine environment, and if so, whether the changes are negative or not.