El Niño ocean warming 'causing havoc' for seals off California coast

Unprecedented numbers of dead or starving seals washing ashore as Pacific Ocean warms, with experts saying they are ‘preparing for the worst’ in 2016

Oliver Milman

Wednesday 30 December 2015 16.52 GMTLast modified on Wednesday 30 December 201516.59 GMT

The warming of the Pacific Ocean caused by the El Niño climate event is “causing havoc” among marine animals off California’s coast, with unprecedented numbers of dead or starving seals being washed ashore.

The San Francisco-based Marine Mammal Center said it has rescued 106 emaciated northern fur seals so far in 2015 – three times greater than the previous record year for rescues. The center said the seals are victim of the exceptionally strong El Niño, which has brought a surge of warm water species, such as red tuna crabs and hammerhead sharks, to California’s coast.

Mothers of seal pups born on California’s channel islands, found west of Los Angeles, are finding it difficult to find their usual prey of sardines and anchovies, which are moving to cooler areas further north to escape sea temperatures that are 2-4C warmer than average.

This means that pups, initially reliant on their mother for nutritious milk, are underweight and understrength when they have to find their own food.

“They can’t dive as deep, they can’t hold their breath as long,” said Dr Shawn Johnson, director of veterinary science at the Marine Mammal Center. “We have been rescuing four-month-old pups weighing 4-5kg, which is typically their birth weight. They should be double that. We are finding pups at record low weights. It’s really worrying for us.

Continued ...

California wildlife: 'Godzilla el Nino' sees turtles, tropical snakes and sharks visit west coast state

Climate change in combination with a monster el Niño this year is attracting some colourful interlopers to the state

Tim Walker

It was early in the afternoon when Dan Maloon, a 34-year-old knife-sharpener from central California, saw what he thought was a white plastic bag floating in the San Joaquin River where he was fishing.

“It caught my attention because the current was flowing the other way,” he said. As the plastic bag drew closer, Mr Maloon began to make out a pair of flippers, propelling it through the water – which is when he realised that it wasn’t a bag at all, but a sea turtle. “That is something you just don’t see unless you are in Hawaii or watching Animal Planet,” he told the Modesto Bee.

The turtle was around 80 miles from the ocean, and more than 1,000 miles from its traditional habitat halfway down the Mexican west coast. Yet that unexpected encounter a week ago was just one of a spate of recent sightings of unlikely creatures in California waters, drawn north by high ocean temperatures.

Last month, a highly venomous, yellow-bellied sea snake was spotted by a surfer on a beach in Ventura County, north of Los Angeles. The snake, aka Pelamis platura, has never been known to venture so far from the Tropics, and is only the second of its species ever found in California. It was added to the collection at LA county’s Natural History Museum (NHM).

Read on ...

Snakebites in Costa Rica Rise Along with El Niño Cycles

by Stephanie Pappas, Live Science Contributor | September 11, 2015 02:06pm ET

In Costa Rica, El Niño has a strange side effect: More snakebites.

Both the hot and cold phases of the El Niño Southern Oscillation (known as El Niño and La Niña, respectively) are accompanied by an increase in snakebites in the Central American country, according to a new study published today (Sept. 11) in the journal Science Advances. Here's how the climate cycle might be tied to slithering creatures:Snakes are ectothermic, meaning they get their body heat from outside sources. That means their activity is sensitive to climatological factors.

"Snakebites, probably the most neglected of the neglected tropical diseases, [are] another disease showing changes in [the] face of climate change," study researcher Luis Fernando Chaves, a scientist at the Institute of Tropical Medicine at Nagasaki University in Japan, told Live Science.

Continued ...

Ancient El Niños triggered Baja bunny booms

Date:

June 4, 2015

Source:

University of Utah

Summary:

At times during the past 10,000 years, cottontails and hares reproduced like rabbits and their numbers surged when the El Niño weather pattern drenched the Pacific Coast with rain, according to an analysis of 3,463 bunny bones.

The study of ancient rabbit populations at a Baja California site may help scientists better understand how mammals that range from the coast to the interior will respond to climate change, says anthropology doctoral student Isaac Hart. He is first author of the study to be published in the July issue of the journalQuaternary Research.

During the past 10,000 years, the number of El Niños per century "correlates very strongly with the total rabbit population in Baja California, as well as relative abundance of the moisture-loving species of rabbits," Hart says.

"There weren't many El Niños from 10,000 to 5,000 years ago," perhaps zero to two per century, says the study's senior author, anthropology professor Jack Broughton. "After 5,000 years ago, there was a relatively dramatic increase in frequency of El Niños in Baja, and the rabbits go through the roof."

Continued ...

Too wet for frogs: changes in a tropical leaf litter community coincide with La Niña - via Herp Digest

Ecosphere Volume 6, Issue 1, Art4 (January 2015).

Mason J Ryan¹, Norman J Scott¹, Joseph A Cook¹, Beatriz Willink², Gerardo Chaves³, Federico Bolaños³, Adrián García-Rodríguez⁴, Ian M Latella¹, and Sally E Koerner⁵

 

1Department of Biology and Museum of Southwestern Biology, University of New Mexico, MSC03-2020,

Albuquerque, New Mexico 87131 USA

2Department of Biology, Lund University, SE-223 62, Lund, Sweden

3Escuela de Biología, Universidad de Costa Rica, San Pedro, San Jose´ 2060 Costa Rica

4Departamento de Botanica, Ecologia e Zoologia, Universidade Federal do Rio Grande do Norte,

59020-100 Natal, Rio Grande do Norte, Brazil

5Department of Biology, Colorado State University, Fort Collins, Colorado 80523 USA

Corresponding author: Mason J Ryan: mjryan42@gmail.com

Abstract

Extreme climatic events such as the El Niño Southern Oscillation profoundly affect many plants and animals, including amphibians, which are strongly negatively affected by drought conditions. How amphibians respond to exceptionally high precipitation as observed in La Niña events, however, remains unclear. We document correlation between the exceedingly wet 2010-2012 La Niña and community-level change in a leaf litter frog assemblage in Costa Rica. Relative abundances of species shifted, diversity and plot occupancy decreased, and community composition differed and homogenized with the onset of La Niña. These aspects remained altered for over 20-months but rebounded to pre-La Niña levels after approximately 12-months. We hypothesize that complex ecological cascades associated with excess moisture caused short-term declines in abundances of species and associated changes in community structure. If additional stressors such as disease or habitat loss are not co-occurring, frog communities can rapidly recover to pre-disturbance levels following severe climatic events.

Link to open access article: http://www.esajournals.org/doi/abs/10.1890/ES14-00352.1

Warmer seas to hit reef fish badly

Warmer seas triggered by the 1997-98 El Niño led to a dramatic drop in the number of reef fish around French Polynesia, scientists have found.

The fish may have starved, because higher water temperatures killed off tiny marine creatures called plankton, which the fish feed on when they're young.

During the El Niño – the second strongest on record – ocean temperatures shot up to 3.5°C above average. El Niño is the name given to the change in the temperature of the eastern Pacific Ocean which can bring huge changes in the world climate.

Scientists are predicting that warmer waters like those typified by an El Niño event will be the norm under climate change. If they're right, this could spell disaster for around 500 million people who rely on coral reef fish either for their food or for tourism.

'This is the same event that wiped out more than half of the Seychelles reefs. It was a substantial El Niño,' says Dr Steve Simpson from the University of Bristol, one of the authors of the study, published in Global Change Biology.

Although climate change is predicted to bring much warmer seas, it's difficult to be sure how this will affect ecosystems.

In this latest study, Simpson and an international team of experts managed to get hold of data on the numbers of coral reef fish in French Polynesia spanning four years – with the 1997-98 El Niño bang in the middle.

'This meant we could look at the effects of the warming and compare that to fish numbers before El Niño warmed the seas,' says Simpson.

Not just that, but the effects of an El Niño are far-reaching, with higher water temperatures happening over thousands of kilometres, and over relatively long periods. So the team realised that combined with the fish data, this was probably the best opportunity they were going to get to find out how reef fish cope with warmer-than-average water.

Simpson and his colleagues analysed satellite data on water temperatures, ocean currents and the amount of chlorophyll in the water from January 1996 to March 2000. Many plankton use chlorophyll to photosynthesize in the same way that plants do, so chlorophyll tells scientists how much plankton is in the water.

They found during the 1997-98 El Niño, water temperatures rose, concentrations of chlorophyll dropped and the direction in which the ocean currents flowed changed around French Polynesia.

But warmer waters didn't just hit young fish badly; lack of plankton may have meant adult fish couldn't produce as many offspring as usual. The team found that once plankton had recovered, it took three to four months before the numbers of young fish started to climb.

'Even after the current switched with El Niño, we still saw young fish on the reef, so the current didn't seem to be the problem. We're fairly sure this is all down to food availability,' says Simpson.

Young reef fish don't grow up on the reef. Instead, after the adults have laid eggs, they drift out to sea, where they feed on plankton until they're developed enough to come back to the reef. The numbers of predators around coral reefs are much higher than out at sea, so the young fish can grow up in relative safety.

Fisheries managers often monitor the numbers of young fish returning to the reef to get some idea of the likely numbers of fish the following season. It was this data that Simpson and his colleagues analysed.

While reef fish could be badly hit by climate change, Simpson is finding that other species, in the northern Atlantic for example, aren't doing quite as badly.

'There's bound to be winners and losers. Some species will find it easy to move north or south as temperatures rise; those that are more mobile. But reef fish are tied to the reef, so they won't be able to move so easily,' adds Simpson. 'It's not a simple story.'

by Tamera Jones

http://planetearth.nerc.ac.uk/news/story.aspx?id=896