Researchers find heat waves are moving toward coasts

By LynnE Friedmann

A Scripps Institution of Oceanography, UC San Diego study suggests that the nature of California heat waves is changing toward more humid heat leading to elevated nighttime temperatures in what were previously cooler coastal areas where most of the state’s population resides. Consistent with climate-change projections, the trend carries major implications for more than 21 million Californians.

Classic California heat waves are characterized by interior desert and valley conditions that are hot and dry during the day with pronounced nighttime cooling. Observations and computer modeling by researchers indicates that greater humidity and greater nighttime temperatures in coastal areas will intensify in coming decades. In other words, what has been considered extreme heat in the past is gradually becoming commonplace.

The trend could lead to a variety of changes in California’s coastal communities, such as the installation of air conditioners in homes traditionally not in need of cooling. This, in turn, would affect energy demand. High humidity and lingering nighttime heat are also expected to lead to more heat-related illness in coastal areas during heat waves unless effective heat-emergency plans are implemented.

— The study appears in the journal Geophysical Research Letters. News release at

http://bit.ly/UgQAMJ

Salk discovery may help protect crops

The most severe drought in 25 years is impacting crops across the United States, with the potential to wipe out farmers’ incomes and raise food prices. Curbing crops’ susceptibility to certain stressors could allow for higher yields during droughts and possibly allow drier climates to support profitable crops and feed the world’s growing population.

This might be possible following the discovery by Salk Institute for Biological Studies scientists of a key genetic switch by which plants control their response to ethylene gas, a natural plant hormone best known for its ability to ripen fruit.

During times of flooding, drought, chilling, wounding, or pathogen attack, ethylene directs plants to make growth adjustments to these adverse changes. The Salk discovery reveals a key step in how plants sense – or “smell” – ethylene gas, which may ultimately lead to ways to manipulate the ethylene on/off switch, allowing plants to thrive in tough conditions.

— Findings appear in the journal Science. News release at

http://bit.ly/QG7Sns

Opah research underway in Eastern Pacific Ocean

Opah, a pelagic fish that occurs seasonally in the Southern California waters, are taken incidentally in both recreational fisheries for tuna and the California drift gillnet fishery for swordfish. In recent years there appears to have been an upsurge in opah catch and the rich meat has become increasingly popular in seafood markets.

Despite their value to commercial and recreational fishermen, little basic biology and ecology of opah is known. To fill data gaps, the Southwest Fisheries Science Center, La Jolla, began collecting biological samples from opah in 2009 and initiated an electronic tagging program in 2011.

Analyses of this data reveals a wealth of information, such as the opah caught off California is a different species than those caught off Hawaii. Opah also appear to have a unique gill arch structure that may explain the fish’s ability to forage to depths of 200 meters.

Such basic life history information will aid future population assessments and management. Combined with historical records, correlations may be uncovered between opah abundance with changes in sea surface conditions such as El Niño and La Niña.

— More information at

http://1.usa.gov/OzjFR5

Lynne Friedmann is a science writer based in Solana Beach.

   
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