Dead Baby Dolphins In Record Numbers

[nismaratwork]

...In the Gulf of mexico.

http://www.cnn.com/2011/US/02/24/gulf.dolphins/index.html?hpt=C1

(CNN) -- Baby bottlenose dolphins are washing up dead in record numbers on the shores of Alabama and Mississippi, alarming scientists and a federal agency charged with monitoring the health of the Gulf of Mexico.

Moby Solangi, the executive director of the Institute for Marine Mammal Studies (IMMS) in Gulfport, Mississippi, said Thursday he's never seen such high death numbers.

"I've worked with marine mammals for 30 years, and this is the first time we've seen such a high number of calves," he said. "It's alarming."

At least 24 baby dolphins have washed up on the shores of the two states since the beginning of the year -- more than ten times the normal rate. Also, six older dolphins died.

In January 2009 and 2010, no calf strandings were reported, compared to four in January 2011, the institute said. During the month of February for those years, only one calf stranding was reported each year.

Blair Mase, lead marine mammal stranding coordinator for the National Oceanic and Atmospheric Administration (NOAA), echoed Solangi's concern.

"It's not common for this time of year to recover such young animals. When you put the numbers together, it's quite high compared to previous years."

The occurrence has prompted NOAA to designate these deaths as an "unusual mortality event" -- defined as a stranding incident that is unexpected or involves a significant loss of any marine mammal population.

While bottlenose dolphins are actually the most-frequently found stranding animal, the season usually begins in March, according to Mase.

"We receive reports of stranding year round. We get an average of 700 total every year in the Southeast," she said.

While scientists have seen baby dolphins wash up in the past, "This is not during the months that they should be," said Solangi. "We keep getting reports of new ones all the time, and February isn't over yet."

There have been 13 unusual mortality events involving dolphin deaths in the Gulf of Mexico since 1991, Mase explained.

Marine mammals are particularly susceptible to harmful algal blooms, infectious diseases, temperature and environmental changes, and human impact, she said.

"Unfortunately we don't have a smoking gun here. We're looking at the possibility of an algal bloom but we don't see any evidence of a bloom going on in the water. Temperatures are a bit cooler, so we're looking into water temperature data and seeing if that has a role, but it's a little bit too early to tell."

Welcome to the reality; we have no idea just how much damage has been done to a truly important ecosystem. True, "no smoking gun", but this is worrying, and I'd expect more to come.

 

[Proton Soup]

meh. 13 events since '91? I'm guessing just another red tide. pretty common occurrence down there.

 

[Amp1]

Just my opinion this speculation, but might this event be tied to an ongoing impact from the BP spill.

 

[mugaliens]

Can we sweep this into the Gulf Oil Spill in general? There is entirely too much lack of data to create or allow widely dispersant threads on this subject.

Yes, Gulf organisms are dying in droves.

Which, where, why, what we can do about it, etc., are all wide open questions. Totally different issue given "what's done is done."

Move out! What can we do next?

 

[Mech_Engineer]

It seems to me that 24 dead baby dolphins, 4 strandings, and 6 dead adults for the ENTIRE GULF is not a statistically significant sample. What's the dolphin population across those two states? Tens of thousands? Hundreds of thousands? Does an uptick of 24 babies in the entire population really show a statistically significant increase in the infant mortality rate for the area?

 

[Amp1]

Right, not for something as big as the gulf. I'm wondering if it is significant that small parts of an ecosystem as massive as the Gulf of Mexico being upset(?) could have an effect on more complex organisms like mammals or large fish? Dispersion is still ongoing there. I think and conservatively speaking there was likely damage to the ecosystem(s) in the Gulf. Is that such a far leap of chain assumptions? Does anyone have info in general?

 

[nismaratwork]

meh. 13 events since '91? I'm guessing just another red tide. pretty common occurrence down there.

I think you misread... 13 since '91

"At least 24 baby dolphins have washed up on the shores of the two states since the beginning of the year."

CONTRAST.

Did anyone ctually read this article?

 

[nismaratwork]

It seems to me that 24 dead baby dolphins, 4 strandings, and 6 dead adults for the ENTIRE GULF is not a statistically significant sample. What's the dolphin population across those two states? Tens of thousands? Hundreds of thousands? Does an uptick of 24 babies in the entire population really show a statistically significant increase in the infant mortality rate for the area?

You don't see a tenfold increase of such a rare event, out of season to be statistically significant? Please tell me your name is a fanciful boast...

 

[Mech_Engineer]

You don't see a tenfold increase of such a rare event, out of season to be statistically significant? Please tell me your name is a fanciful boast...

Please read into the concept of statistical significance, specifically the following:

In statistics, a result is called statistically significant if it is unlikely to have occurred by chance.
...
Many researchers urge that tests of significance should always be accompanied by effect-size statistics, which approximate the size and thus the practical importance of the difference. [emphasis added]

The point is that first, your post is not a peer-reviewed study it's some anecdotal evidence provided to a news station. Your implicit claim is that these dolphins are dead as a result of the oil spill several months ago, but this isn't known without an autopsy. Secondly, they are dead but is it a statistically significant portion of the population or an isolated incident perhaps due to unusual breeding patterns?

 

[Amp1]

Following the Deepwater Horizon rig explosion last April, which killed 11 workers and caused the worst oil spill in U.S. history, there has been heightened concern over the environmental impact.
Due to the government's ongoing litigation with BP, which owned the oil well that erupted into the Gulf of Mexico, NOAA said it must operate under specific protocol in handling the dead dolphins. That might mean a delay in seeing the necropsy results.
"In a world when we wouldn't be dealing with oil-spill protocols, we'd typically get results in about three weeks to a month," Mase said. "We aren't going to see results as quickly as we'd like to. We will be making sure these samples are collected, taken back and analyzed, but it could take several months."
While none of the 30 dolphins were found with any oil on them, Mase said the agency is not ruling anything in or out on the cause of death.

I'm probably jumping the gun, but shouldn't the tests and analysis be done as promptly as possible despite any protocols with BP or ongoing litigation. Establishment of facts either pertinent to the litigation or not what happens in the Gulf affects all the States along its coast.

 

[nismaratwork]

Please read into the concept of statistical significance, specifically the following:



The point is that first, your post is not a peer-reviewed study it's some anecdotal evidence provided to a news station. Your implicit claim is that these dolphins are dead as a result of the oil spill several months ago, but this isn't known without an autopsy. Secondly, they are dead but is it a statistically significant portion of the population or an isolated incident perhaps due to unusual breeding patterns?

Ahhh, so now you question the source, fair enough, but of course I only presented this as what is... a news story including the information marine biologists gave to said organization. I suppose a random change in breeding that isn't linked to any known weather pattern or other factor could be at play, but what's causing that? Could be a fallacy of proximity, but it seems more than a little odd to me. Still, that’s not a point I need to defend, because I never made it.

Welcome to the reality; we have no idea just how much damage has been done to a truly important ecosystem. True, "no smoking gun", but this is worrying, and I'd expect more to come.

So, I’m not sure where you see me trying to pass preliminary indications as anything other than preliminary indications. If you can find that, please let me know.

I'd add, 13 in 10 years, and then about 30 in less than a year, again, "out of season" is more than a little odd, and that assumes you went no further in your statistical analysis than the one example I gave in a casual post. You're going to have to wait for studies, because these things take time both to emerge, and to be studied. In the meantime, if you dismiss every development not studied, you’re going to be unable to head off even obvious damage. I don’t feel that waiting for clinical trials on the scale of the gulf is a wise idea, but then, that’s just me… and marine biologists… and NOAA.

Oh yes… when you dissect a dead animal to explore causes of death, it's called a NECROPSY, and I wouldn't expect to find smoking guns at this point (to quote my OP…again). Again. You have an odd habit of applying the standards of your field to those in which your knowledge is unclear (necropsy being a fine give-away). You'd do as well trying to sell reasonable doubt in civil court, or preponderance of evidence in a criminal court.

The practical importance here is that you have a sample size that is extremely large given that these corpses tend to be eaten by predators, hence some of the rarity. I'd add, statistical models for dolphin deaths exist, and no, I'm not digging for them: there's a reason this is in P&WA and not Biology; this is preliminary, but worrying.

 

[Proton Soup]

I think you misread... 13 since '91

"At least 24 baby dolphins have washed up on the shores of the two states since the beginning of the year."

CONTRAST.

Did anyone ctually read this article?

well, I'm not reading "events" as individual dolphins, if that is what you mean.

and I'm not exactly sure how many events these 24 are meant to represent.

 

[mugaliens]

It seems to me that 24 dead baby dolphins, 4 strandings, and 6 dead adults for the ENTIRE GULF is not a statistically significant sample.

Seems to me you're ignoring basis stats given the far greater input as reported by the article.

 

[mugaliens]

You don't see a tenfold increase of such a rare event, out of season to be statistically significant? Please tell me your name is a fanciful boast...

Any time a populuation mortality exceeds 100% its previous levels, it's serious cause for concern. It it's 1,000, things abound which deserve national attention.

 

[russ_watters]

Any time a populuation mortality exceeds 100% its previous levels, it's serious cause for concern. It it's 1,000, things abound which deserve national attention.

You're missing the point, mugaliens. Unless there are only a few dozen dolphins in the entire gulf, many more than a couple a year are dying. What they aren't doing - and what is new here - is that they are washing up on the beach. So without knowing how many baby dolphins die in the gulf every year, it is impossible to know how significant of an event this is. Heck, it isn't even necesary for these to be extra deaths! I can speculate about a lot of different reasons why more dolphins might wash up on shore without there necessarily even being more deaths. I don't like being too speculative about something I really don't find compelling at the moment, but I'm sure people will want something, so:

Perhaps dolphins are swimming closer to shore for some reason so when they do die, they wash up whereas they didn't before.

Part of the problem is the title of the thread: Scientists haven't found more dead baby dolphins in the gulf, only on the shores of the gulf.

 

[nismaratwork]

You're missing the point, mugaliens. Unless there are only a few dozen dolphins in the entire gulf, many more than a couple a year are dying. What they aren't doing - and what is new here - is that they are washing up on the beach. So without knowing how many baby dolphins die in the gulf every year, it is impossible to know how significant of an event this is. Heck, it isn't even necesary for these to be extra deaths! I can speculate about a lot of different reasons why more dolphins might wash up on shore without there necessarily even being more deaths. I don't like being too speculative about something I really don't find compelling at the moment, but I'm sure people will want something, so:

Perhaps dolphins are swimming closer to shore for some reason so when they do die, they wash up whereas they didn't before.

Part of the problem is the title of the thread: Scientists haven't found more dead baby dolphins in the gulf, only on the shores of the gulf.

Mmmmm... I wonder if that has anything to do with a baby dolphin in the gulf being stripped by scavangers almost immidiately? It is exceedingly odd that so many should wash ashore dead, yet relatively untouched by scavangers. It could be closer swimming, it could be any number of reasosns as yet unkown.

That said, what would your recommendation for the title of the thread be? I'm open to suggestions if you found it misleading in the context of the OP and news story. I'm also laughing at the same time, because anyone who was so mislead obviously didn't read any of it.

So, if dolphins in general are swimming closer to shore, why are only calves washing up, and not adults? Why also, is this happening out of season? You're being painfully selective in what you respond to, and the manner in which you've chosen to re-frame matters does not really offer anything tangible. Beyond that, see my response to Mech-Engineer, because frankly, I think you're not missing the point, you're dodging it.

 

[nismaratwork]

Any time a populuation mortality exceeds 100% its previous levels, it's serious cause for concern. It it's 1,000, things abound which deserve national attention.

I would tend to agree, especially as NOAA, and indipendant marine biologists are both puzzled and concerned, and given the rarity of any ONE calf being beached, dead.

Then again, I think some here are responding to claims they think are in the works, not claims that have been made.

 

[Mech_Engineer]

I personally think the title of the thread is fine, it simply reflects the title of the news article...

Any time a populuation mortality exceeds 100% its previous levels, it's serious cause for concern. It it's 1,000, things abound which deserve national attention.

The problem is this doesn't address the population mortality in the entire gulf, only that more have washed up on the beach in the first part of this year. If this did reflect population mortailty in the Gulf (it hasn't been proven to, but even if it did...) it certainly wouldn't reflect a 100% or 1000% increase in mortailty. There's a big difference between "increase in number of dead individuals" and "increase in population mortailty rate."

You're missing the point, mugaliens. Unless there are only a few dozen dolphins in the entire gulf, many more than a couple a year are dying. What they aren't doing - and what is new here - is that they are washing up on the beach. So without knowing how many baby dolphins die in the gulf every year, it is impossible to know how significant of an event this is. Heck, it isn't even necesary for these to be extra deaths!

Exactly, the death record for beached dolphins doesn't seem to be statistically significant because it's unknown how it relates to the total number of dolphin deaths in the gulf.

 

[nismaratwork]

I personally think the title of the thread is fine, it simply reflects the title of the news article...



The problem is this doesn't address the population mortality in the entire gulf, only that more have washed up on the beach in the first part of this year. If this did reflect population mortailty in the Gulf (it hasn't been proven to, but even if it did...) it certainly wouldn't reflect a 100% or 1000% increase in mortailty. There's a big difference between "increase in number of dead individuals" and "increase in population mortailty rate."



Exactly, the death record for beached dolphins doesn't seem to be statistically significant because it's unknown how it relates to the total number of dolphin deaths in the gulf.

Yet it is statistically significant when compared to the last (choose any period of time you like) years. That's the joy of statistics... you can make them dance by what you compare them to, but then, there is no claim being made that MORE dolphins are dying, so that simply isn't a valid concern.

As I keep pointing out, the oddities so far cannot be used to extrapolate that, but given time it may well be so. Right now, the issue is why calfs are washing up whole, washing up in such numbers, and out of season.

Your "***%" increase in mortality is not a claim that I believe anyone has made here. Straw... Man...

 

[Borek]

Exactly, the death record for beached dolphins doesn't seem to be statistically significant because it's unknown how it relates to the total number of dolphin deaths in the gulf.

While I agree with you when it comes to dolphin deaths/population, observed change means SOMETHING has changed. What it is - is another problem.

 

[nismaratwork]

While I agree with you when it comes to dolphin deaths/population, observed change means SOMETHING has changed. What it is - is another problem.

YES! Thank you...

I'd also agree that "what" is going to take time, and "why" will take years more. I personally find myself believing that it's the BP spill, but I'm wary of the fallacy inherent there.

Still, these issues may continue, and it's gathering and comparing them that we need to be aware of, even if it's too early to draw conclusions. This may be the tip of an iceberg, or we could be lucky and this was something to do with La Nina, or an algae bloom due to runoff.

 

[Mech_Engineer]

Yet it is statistically significant when compared to the last (choose any period of time you like) years.

As I pointed out, for a result to be statistically significant it must be shown to have a low probability of occurring by chance. You are incorrectly assuming statistically significant means "large change."

Your "***%" increase in mortality is not a claim that I believe anyone has made here. Straw... Man...

I'm simply pointing out that there is a big difference in the two meausres, and one "seems" a lot bigger than the other.

If you have a dolphin population of 10,000, and normally 25 die per year that's a mortality rate of 0.25%. If the next year 50 die, the mortality rate doubles to 0.50% (an increase of 0.25%), but the percent increase in dead individuals was 100%. See the difference?

 

[nismaratwork]

As I pointed out, for a result to be statistically significant it must be shown to have a low probability of occurring by chance. You are incorrectly assuming statistically significant means "large change."



I'm simply pointing out that there is a big difference in the two meausres, and one "seems" a lot bigger than the other.

If you have a dolphin population of 10,000, and normally 25 die per year that's a mortality rate of 0.25%. If the next year 50 die, the mortality rate doubles to 0.50% (an increase of 0.25%), but the percent increase in dead individuals was 100%. See the difference?

Again, interesting stuff, but you're missing the point: this isn't yet a question of overall mortality, it's a question of THIS particular anomoly.

edit: I'd add... given the enormous sample size (recorded history), and the other oddities I keep mentioning, an you keep ignoring... there is statisitical significance. There is no record of such an event in anything CLOSE to these number, the lack of predation by scavengers, and the season. You can simply bull on ahead, but it does you no credit, nor does it help you make a point.

What is your point by the way? Doubt? There's plenty of that; this is just a single datapoint, but ignoring each as they arise is a fine way to create ignorance.

 

[russ_watters]

I personally think the title of the thread is fine, it simply reflects the title of the news article...

It's those three little words in the first line of the article that were dropped when paraphrased into the title of the thread that make up the entirety of the statistical issue we're discussing!

Opening sentence of the article: "Baby bottlenose dolphins are washing up dead in record numbers on the shores of...the Gulf of Mexico."

OP Title/Subtitle: "Dead Baby Dolphins In Record Numbers in the Gulf of Mexico"

Your "***%" increase in mortality is not a claim that I believe anyone has made here. Straw... Man...

Well, yes - mugaliens made it and it may well be because your misleading title/subtitle implies it by its alteration of that phrase: unless the population of dophins is growing, the only way for there to be more dead baby dolphins in the gulf of Mexico is for more to be dying.

Any time a populuation mortality exceeds 100% its previous levels, it's serious cause for concern.

 

[nismaratwork]

It's those three little words in the first line of the article that were dropped when paraphrased into the title of the thread that make up the entirety of the statistical issue we're discussing!

Opening sentence of the article: "Baby bottlenose dolphins are washing up dead in record numbers on the shores of...the Gulf of Mexico."

OP Title/Subtitle: "Dead Baby Dolphins In Record Numbers in the Gulf of Mexico" Well, yes - mugaliens made it and it may well be because your misleading title/subtitle implies it by its alteration of that phrase: unless the population of dophins is growing, the only way for there to be more dead baby dolphins in the gulf of Mexico is for more to be dying.

Once again, for a second time I'll offer to have it changed to whatever better suits you. If you can't get past the title, you do realize that doesn't bode well for your credibility? I didn't create the title to be misleading, I accept that it can be, and this is now the second time I've offered to change it to whatever you like, and you have that ability.

To say that you're not acting in good faith, is an understatement, but beyond that you're actually failing to add anything to this except derailment. If you have a problem with an assertion made by another, take it up with them. If you have a problem with the title, change it. If you have a problem with me... guess.

I'd add, you might want to focus on the OP, and less on the title if it so offends you. Remember this?... it was only a few posts ago...

That said, what would your recommendation for the title of the thread be? I'm open to suggestions if you found it misleading in the context of the OP and news story. I'm also laughing at the same time, because anyone who was so mislead obviously didn't read any of it.

Remember Russ?