By Knut Yngve Børsheim
The initial impacts of ocean acidification can be seen in the problems caused for shell-forming organisms such as corals, snails, and shellfish. Today the ocean is only slightly over-saturated with calcium carbonate, but if CO2 emissions continue at the current rate the upper water masses will become under-saturated.
A Formidable Task
The chemical processes that lead to ocean acidification are well understood, but how these processes affect marine ecosystems has not been well studied. The project:”Marine Ecosystem Response to a Changing CLIMate (MERCLIM)” was initiated in 2008 to study the potential response of marine ecosystems to ocean acidification. This is an enormous task, and the project is part of a larger international collaboration. During summer 2009, physiological experiments were carried out in Fram Strait to investigate the response of zooplankton and phytoplankton to levels of ocean acidification expected during the next 10 years. This project was done through collaboration between the Institute of Marine Research (IMR) and the Bjerknes Center for Climate Research in coordination with the European Project on Acid Acidification (EPOCA).
Flight of the Sea Butterfly
Considering the many questions relating to this topic, too little research has been conducted on the effects of ocean acidification. However, this we can address. IMR researchers are adept at gathering insight into biological response to ocean acidification. The laboratory at Matre has recently been modernized with new instruments to simulate future conditions in ocean chemistry, and is now well-positioned to conduct critically-needed experiments ― primarily to learn how important elements of the marine food web are impacted by ocean acidification. First on this list are species of krill and copepods due of the central role these organisms play at the base of the food web. Special focus is also placed on the sea butterflies. These animals form their shells using argonite; this mineral dissolves in marine waters that are under-saturated with calcium carbonate. It is well known that sea butterflies play an important role in the marine food web, particularly at high latitudes. Decreased levels of abundance for these snails would substantially impact marine ecosystems, and the fishery resources that they support.
A Fundamental Approach to this Problem
It can be expected that managers will look for concrete prognoses for the effects of ocean acidification on central components of marine food webs. Therefore, it is natural to build our understanding around important prey species such as copepods and krill, together with mollusk such as butterfly snails and shellfish. It is essential that we determine how reproductive processes and rates of survival for eggs and fry will be affected by ocean acidification. Additional required information will be its influence on primary productivity. Changes in species assemblages and patterns of succession can be envisaged in communities of phytoplankton. Possible effects of ocean acidification pose fundamental questions to our understanding of plankton ecology. For this reason, research that has been initiated on this question is well suited to existing IMR approaches to ecosystem-based resource management.