The US federal agency tasked with monitoring oceans and climate, the National Oceanic and Atmospheric Administration (NOAA), yesterday announced a seven step plan to gather and codify scientific evidence for the nature, scale and pace of climate change to better predict its effect on the oceanic regions and fisheries under US jurisdiction. But the atmosphere and the oceans are global systems, and NOAA’s strategy takes this into account, said climate change coordinator Roger Griffis.
“One of the challenges with our management of fisheries and other marine resources has always been how to manage things in a changing world,” Griffis told NutraIngredients-USA. “There are two main stressors of oceanic systems at the moment, and those are rising ocean temperatures and increasing acidification.”
A question of temperature and pH
Climate change theorists point to a common cause for these conditions, that being the increased pace of the burning of fossil fuels over the past two centuries and the resulting rise in carbon dioxide levels in the atmosphere. That excess CO2 ends up in three places: it remains in the atmosphere, where it acts as a potent greenhouse gas; it is taken up in plants; or it dissolves into the world’s oceans, where it leads to a gradual rise in acidity over time. The CO2 that remains in the atmosphere affects the oceans, too, with increasing temperatures at sea level leading to a rise in ocean temperatures.
“The change in ocean temperatures is of more concern at the moment because we are seeing those changes occur very rapidly,” Griffis said. “There are about 10 major hotspots around the globe for ocean temperature rise.”
Oceanic hotspots
Among those hotspots are the polar oceans, especially the Arctic Ocean. One way to visualize this is the extent of sea ice. This decade has seen the smallest average ice cover in the Arctic Ocean since measurements began. According to the National Snow and Ice Data Center at the University of Colorado Boulder, ice coverage in the Arctic Ocean on August 16, 2015 stood at at 5.79 million square kilometers (2.24 million square miles). This is 1.35 million square kilometers (521,200 square miles) below the 1981 to 2010 average, and 1.17 million square kilometers (451,700 square miles) above the level for the same date in 2012, the year of the record low extent. Sea ice extent is now tracking below 2010, 2013, and 2014.
Polar oceanic conditions are of concern for the supply of omega-3 ingredients on several fronts. The Norwegian cod and Alaskan pollock fisheries are contributors to the global supply of raw materials for these ingredients. And more recently the krill fishery in the far southern Atlantic Ocean has been a source of supply of krill oil omega-3 raw material.
“Another hot spot is the Atlantic Ocean along our northeastern coast of the US, particularly along the coast of Maine. The ocean is warming there faster than in any other place,” Griffis said.
But the big concern for the omega-3s supply picture is the effect of ocean temperature rise for the world’s major upwelling systems, including those off the western coast of the US and off the western shores of South America. The Peruvian anchovy fishery continues to supply the raw material for about 70% of the world’s servings of omega-3 supplements.
Imperfectly understood cycles
This upwelling of cold water via the Humboldt Current gives rise to an enormously productive fishery, with untold trillions of short-lived and fast-growing anchovies gathering in dense schools to feed on the rich plankton growth made possible by the nutrient-dense, cold waters. But the system is subject to periodic disruptions via El Niño events, in which a huge pool of warm water forms in the eastern Pacific Ocean off South America, causing a crash in anchovy numbers and major changes in precipitation patterns in North America and elsewhere. Another longer-term cycle affecting the system is known as the Pacific Decadal Oscillation. Both cycles are imperfectly understood.
“We are seeing a major El Niño event play out even as we speak. We might be seeing a preview of what the new norm in that system will look like. Tracking the pulse of change in systems like this is one of the foundational rungs of our climate change strategy,” Griffis said.
Assessing variability
One issue with tracking these changes is the dearth of solid baseline data, said fisheries researcher Ray Hilborn of the University of Washington. In his view some major historical fish population crashes, such as the virtual disappearance of large sardine schools off of California, might be in the long-term cyclical nature of these populations and have been affected in only a minor way by human activity.
“Is it a climate change issue or a natural variability issue? We know from fossil records that for thousands of years the sardines have basically come and gone. From the record we have seen that the sardines have been almost absent for decades, sometimes as much as fifty years at a time.The decline that has happened was going to happen, and the number of fish that fishermen took may have only speeded it up a little bit. A lot of these pelagic resources undergo a very strong natural fluctuation,” he said.
Getting to a baseline
Hilborn’s observations point to a criticism that climate change naysayers level at researchers in the field, namely that changes the researchers attribute to human activity may in fact be part of bigger, longer-term natural cycles (the intent here, by the way, is not necessarily to lump Hilborn in with the naysayers).
It’s a criticism that federal managers are sensitive to, Griffis said, and is one of motivators for the recently announced strategy. The seven bullet points of the plan, each building on the next, are:
- Climate Informed Reference Points
- Robust Management Strategies
- Adaptive Management Processes
- Project Future Conditions
- Understand Mechanisms of Change
- Track Change and Provide Early Warnings
- Science Infrastructure to Provide Actionable Information.
The ultimate goal, Griffis said, is to have a more solid foundation on which to make management decisions. Even though some of those decisions could potentially be painful ones for the harvesters of marine resources, Griffis said NOAA has experienced a gratifying amount of buy-in from industry stakeholders.
“This is about building out our scientific capacity to improve our ability to manage even normal cycles. We have enough evidence to know that oceanic systems are beginning to change and in some cases change rapidly. We are seeing a growing demand for information (from industry stakeholders) and we are excited about that. We would like to have them as partners in the process. As a matter of business practice they want to know what the cycles are and where they stand within those cycles to plan investment decisions. The worst case scenario for all concerned would be if we are doing fisheries stock assessments and determining quotas using information that doesn’t reflect reality,” he said.