The first time I heard the term “sea heat wave”, I said we call it El Niño. A wave of sea cold is called La Niña. In fact, these two linked events are the setbacks of what scientists call the El Nino-Southern Oscillation, which is a well-known climate pattern in the Pacific Ocean, and to which we as fishermen have found our way to adapt and derive. left.
Amberjack like these caught by Captain David Bacon and charter passenger Sarah Crandall are found in the Santa Barbara Channel during marine heat waves. (Courtesy picture)
The El Niño Southern Oscillation is the most famous, infamous, and sometimes most unpredictable of a global phenomenon called marine heat waves or MHWs. These occur when ocean temperatures are much warmer than usual for an extended period of time. They are specifically defined by the expected (normal) temperature differences for a given location and time of year.
There have been many MHWs, and we’ve been surprised and perplexed by some, like the infamous “Blob” that emerged around 2013 in the northeast Pacific Ocean and persisted until 2016. It has resulted in shifting fish stocks, harmful algal blooms, entanglements of endangered humpback whales and thousands of starving sea lion babies washing up on beaches.
The Blob served as a wake-up call to researchers and ocean anglers as it disrupted our typical patterns and caused widespread damage and disruption of fishing opportunities. A public statement from NOAA said this marine heat wave led to an ecological cascade in which whale prey was unusually concentrated near the shore, and a severe toxic algal bloom along the coast delayed the opening of the valuable Dungeness crab fishery.
The Blob was not alone, and marine heat waves are on the rise around the world. According to NOAA, the global annual number of MHW days has increased by 54% over the past century, with eight of the 10 most extreme MHWs on record occurring after 2010.
MHWs are potent stressors with large-scale impacts on marine ecosystems, including driving species range shifts and mass mortalities and altering food webs and species interactions.
The impacts of marine heat waves have been documented in ecosystems around the world, particularly over the past decade. NOAA says these include:
The decline of fish and shellfish that has caused global fishing losses of hundreds of millions of dollars.
Changing distribution of marine species which has increased human-wildlife conflict and disputes over fishing rights.
Extremely hot waters that caused massive coral bleaching and mortality.
Biological responses to MHWs can increase human-ocean interactions, providing benefits and opportunities for sports enthusiasts and, therefore, coastal industries and communities. For example, the cyclical events of El Nino have taught anglers to expect their local waters to contain fish that they typically must travel far south to find (such as dorado appearing off CenCal and NorCal and even off Oregon) increasing tourism and fishing opportunities.
During El Niño and other MHW events, swimmers, snorkelers, and surfers may find the water a little more comfortably warm than usual. This tends to encourage people to take advantage of seaside tours more often, which benefits coastal economies as locals and visitors spend more on amenities such as surfboards and scuba gear. I took advantage of this as a former owner of Hook, Line & Sinker in Santa Barbara.
– Captain David Bacon operates WaveWalker Charters and is President of SOFTIN Inc., a non-profit organization providing boating opportunities to those in need. Visit softininc.blogspot.com to learn more about the organization and how you can help. Click here to read previous columns. The opinions expressed are his own.