Scientists ask: Where have all the dolphins gone?

www.physorg.com...

Sightings by marine scientists of dolphins in the north Atlantic's Bay of Biscay have dropped off by 80 percent compared to the same period in 2006, a wildlife conservation group said Wednesday.

More...

The fact that this drop could happen within a single year is very disturbing, to say the least.

So long and thanks for all the fish...

The source states that dolphins have been killed in large numbers by pair trawlers, the dolphins are getting caught in the nets which means they are then unable to surface to breathe.

Another reason for the reduction of dolphins in the area is that they've simply followed their food, with a reduction of fish in the area of the Bay of Biscay there simply aren't enough fish to sustain the number of dolphins so they've moved on to areas with more fish.

The fact its happened in one year may simply be down to this years sightings being down rather than the actual dolphin population.

[edit on 23-8-2007 by UK Wizard]

OR.... They(Dolphins) know something we don't. Maybe the dolphins are just... somewhere else...

I can say all is well over here in the gulf. I have a little fishing spot here in florida called Anclote island.

I go out to the park and when we dont feel like bringing in the skiff, we just walk out waist deep and do our fishing in the waters there.

Every time I am out there, we see dolphins, sometimes 4 of them at a time. Its really kewl, becasue they jump around and play, keep the bullsharks away! And if theirs dolphins, you can bet its great fishing Im out there atleast 1 time a week, and always see them.

So its 95% rate of just me seeing them. And its a large family of them, and have been around for the last 5 years.

Both reasons are speculation.

Originally posted by UK Wizard
The source states that dolphins have been killed in large numbers by pair trawlers, the dolphins are getting caught in the nets which means they are then unable to surface to breathe.

Were these trawlers just introduced this year?

Originally posted by UK Wizard
Another reason for the reduction of dolphins in the area is that they've simply followed their food, with a reduction of fish in the area of the Bay of Biscay there simply aren't enough fish to sustain the number of dolphins so they've moved on to areas with more fish.

Even in the source article it states:

"Anchovy fishing in the Bay of Biscay has progressively failed, and this year there is a complete ban by Spain, France and the United Kingdom on the fishing of anchovies," a principal food source for dolphins, Clive said.

He speculated that the roving sea mammals -- which swim in pods numbering in the dozens for bottlenose dolphins, and sometimes in the thousands for the common dolphin -- had moved west toward the mid-Atlantic looking for food.

If Spain, France and the United Kingdom introduced a ban on the fishing of anchovies, there would be less competition for the food supply...and therefore MORE food for the dolphins.

He uses rather odd logic in his speculation, if you ask me.

Originally posted by UK Wizard
The fact its happened in one year may simply be down to this years sightings being down rather than the actual dolphin population.

That makes no sense to me.

The Bay of Biscay Research Programme has been systematically recording dolphin sightings along the same route from Bilbao, Spain to Portsmouth, England for 13 years.

Cut it any way you want.... The fact there could be such a dramatic difference in the period of a single year is startling.



[edit on 23-8-2007 by loam]

I just got back from a trip in Maui, HI. Went on a dolphin/snorkling cruise. We saw at least 50 spinner dolphins that stayed near our ship. Granted this doesn't really conclude anything, I figured I would mention it. Plus, Spinner Dolphins always stay together, so seeing that many also isn't indicitave of a steady population.

It should be noted that all sightings are based on one ships progress - a P&O liner and this is where the project is based

reply to post by Cloak and Dagger


Your right, and I do understand that the dolphins are having a hard time when living with man.. Ive been in some very heated discussions about dolphins, and how they suffer from many of mans deeds.
Its a big problem, and glad to see the OP giving this some attention. They are in my eyes = to humans, and should be treated as such..

Originally posted by Silk
It should be noted that all sightings are based on one ships progress - a P&O liner and this is where the project is based

Let's be a little more clear:

www.biscay-dolphin.org.uk...

Originally posted by UK Wizard
So long and thanks for all the fish...

My thoughts exactly...

This could tie up several loose ends on the conspiracy side. Them dolphins are smart... apparently real smart... they discovered invisibility...

One summer's drop in dolphin sightings does not a catastrophe make.

We also have to keep in mind that marine animals like dolphins -- even the great white shark -- migrate. As was previously mentioned, access to food is the primary reason for migration.

Nature isn't static. Animals don't stay in the same place. Perhaps this year Biscay Bay is "out" as far as dolphins are concerned and they're summering elsewhere. Found a new hot spot with better sushi.

Whatever is going on, it's premature to panic about it.

Originally posted by MajorMalfunction
We also have to keep in mind that marine animals like dolphins -- even the great white shark -- migrate. As was previously mentioned, access to food is the primary reason for migration.

It is because these dolphins RARELY migrate that such a significant seasonal drop is noteworthy.

Lumping dolphins- particularly the bottlenose- to the migration behavior of other cetaceans and a fish is just flat wrong.

Distribution and Migration: Bottlenose dolphins are found worldwide in temperate and tropical waters, absent only from 45 degrees poleward in either hemisphere. They are frequently seen in harbors, bays, lagoons, estuaries, and river mouths. There appear to be two ecotypes: a coastal form and an offshore form. Population density appears to be higher nearshore. Biochemical studies now are providing more information about the relationship within and between the ecotypes. In some areas, dolphins have limited home ranges; in others, they are migratory. A second species Tursiops aduncus, inhabits the Indian Ocean.

www.acsonline.org...

Apparently some bottlenose do migrate. How do you know which variety are missing in Biscay Bay?

If there are still no dolphins there next year, and the year after that THEN I'll be more willing to admit that something has happened to them other than their taking a hiatus. But I don't like to jump to conclusions about things like this until there is actual evidence something has happened.

[edit to add bold in quote]


[edit on 23-8-2007 by MajorMalfunction]

Let's put it this way...

Are you aware of any cetacean migration patterns that occur in 13 year cycles?

From another source:

But this summer, sightings of the cetaceans are down by as much as 80 per cent, along the ferry's route. Auks, gannets, and shearwaters are also in short supply. The research groups says populations showed no sign of picking up through August, and is concerned that the decline might be indicative of a bigger problem.

"Whatever the cause of the disappearance of dolphins this summer, it shows both how vulnerable they are and how alarmingly quickly local declines can occur when environmental conditions change," said the group's research director Dr Tom Brereton.

Why are you so quick to dismiss the alarm indicated by the scientists who actually studied the problem?





[edit on 23-8-2007 by loam]

If only they could talk...I wonder if they're hiding out for some reason?

Too much is happening all at once.

They've up and left Earth because they've just picked up a Sub-Ether Radio transmission stating that our planet has been scheduled for demolition to make way for a new hyperspace bypass. Their last message went something like this.



Sorry I couldn't resist.

reply to post by UK Wizard


haha hitch hikers guide to the galaxy

reply to post by dgtempe


If the dolphins leave the coastal waters, then it is a pretty good idea that human beings should leave the coastal lands.

I have a bias in favour of dolphin wisdom...

Could this be related to the slowing down of the Atlantic Conveyor Belt? I mean if it's true that the current carrying warm, nutrient laden waters from the tropics have slowed down, wouldn't that lead to less plankton, which in turn leads to less anchovies, which then leads to less dolphins in the area?

Just a thought.

It probably has a small effect, but I think overfishing is far more damaging. It's a double whammy. Their food gets caught by us and in the process of feeding they get drowned when they get caught in the nets.