Toxic Algae Bloom suspected in hiking family’s death !

What it looks like: Just google “toxic algal bloom” images.

Can you filter it out?  Water filters do not filter out chemicals so I doubt it. But perhaps some expert will post here.

Upstream/downstream.  In Portland there are warning signs all along the Willamette River to keep dogs out of the river  because of the  algal toxin even in places where there is no algae to be seen.

https://www.cdc.gov/habs/prevention-control.html

Don’t know much about toxic algae but it seems weird it would take out all four of them at once.  I heard someone propose a lightning strike.

I hope they find out.

From the CDC site that John S. posted:

It is not possible to know if a large growth, or bloom, of algae or cyanobacteria (also called blue-green algae) is harmful just by looking at it. Some blooms make toxins (poisons), which can still be in the water even when you can’t see a bloom.
…
While no human deaths caused by cyanobacteria have been reported in the United States, many dog deaths have been reported after dogs swam in or drank fresh water containing cyanobacterial toxins. For dogs and other animals, some cyanobacterial toxins can cause illness or death in hours to days.

From SFGate today:

The Mariposa County Coroner’s Office was only able to rule out acute trauma, such as stabbing, gunshot wounds or blunt-force trauma. Toxicology results are expected in two to three weeks.

Other reports said there was no lightning in the area around that time.

Those deaths are still a mystery.

— Rex

Harmful algal blooms can produce a wide array of cyanotoxins that can’t all be removed by backpacking water treatment systems, including boiling, filters, chemicals, or UV. And some treatments make the problem worse.

Life is full of risks. This one seems extremely unlikely.

— Rex

Cyanobacterial Harmful Algal Blooms (CyanoHABs) in Water Bodies, EPA
https://www.epa.gov/cyanohabs

Summary of Cyanotoxins Treatment in Drinking Water, EPA
https://www.epa.gov/ground-water-and-drinking-water/summary-cyanotoxins-treatment-drinking-water

The family was found on a trail, two miles from their car with the wife 30 yards from the others (not sure if she was out front on the hike). The husband was found sitting up-ish with the baby in a carrier next to him and the dog. It was a dayhike (I think) so you would have taken your own water. Some harmful gases can be in low lying areas, but it seems unlikely. I figure most fatal lightning strikes would have entrance/exit wounds.

Direct hit type lightning strikes would certainly leave a mark.  However, there are cases of indirect strikes that kill but don’t leave burns.

Gasses?

“Investigators have considered whether toxic gasses, toxic algae and carbon monoxide from abandoned mines near in area may have contributed to the deaths,” Mariposa County Sheriff’s spokeswoman Kristie Mitchell told Fox News.

A hazmat situation was declared Tuesday related to the abandoned mines but was eventually lifted.

Following this story. So no humans in the U.S. have died yet from cyanotoxins but in this case three did and quickly? Symptoms include vomiting and diarrhea – wouldn’t the campsite offer some clues there? Maybe not published in the story though. I suspect the toxicology report might find something altogether different. I hate to have another thing to worry about!

“So no humans in the U.S. have died yet from cyanotoxins but in this case three did and quickly? ”

No KNOWN deaths from cyanotoxins. There could be UNknown ones though. And it is my understanding that they were day hiking… no camp. And the mother was 30 yards ahead on the trail… so unlikely a lightening strike, I think.

It is scary. But… I’m not sure, but I think this toxic algae grows in hot areas where water gets warm; probably not up high in the mountains. But I am not sure of anything…

A link to a google map of the location

Is the water level low enough currently for the S. Fork of the Merced to be sort of separated into sections of barely flowing pools? Hard to picture cyanobacteria getting bad enough in a flowing river to be toxic to someone(s) taking a dip but I can certainly see it getting hot enough to foster growth of algae, especially if it’s barely flowing.

Clicking on the ‘attractions’ link for the trail and looking at the photos there are several showing mining equipment/machinery from old mines along the route which google maps also names as the Hites Mine Rd. Maybe they ventured into an old mine shaft but then left, walked a ways and then succumbed to gasses?

None of this makes much sense.

“Four dogs have died recently in the Spokane area after swimming in water where toxic algae blooms were confirmed, according to the Washington state Department of Health.

Usually toxic algae blooms are found in lakes, but they were swimming in the Little Spokane River and the Spokane River, both of which have had warm, slow moving and stagnant waters.”

Read more here: https://www.tri-cityherald.com/news/local/article253469409.html#storylink=cpy”

Way outside my area of expertise (but when has THAT prevented anyone from posting), but it seems to me that if it were a gas event that quickly overtook all of them (and the dog) that you’d find other evidence in the form of dead birds and other animals nearby.  Remember the canaries in the coal mines (or was that just a Pennsylvania thing)?

I’ve heard it is the floating blue-green algae blooms that can produce cyanotoxins.

As many have mentioned, most of our backcountry water treatment techniques will not remove the chemicals the algae produce. One thing that can remove the chemicals is an active carbon filter. No one seems to be willing to give guidance on how effective they are because I think there are just too many variables.

This article is accurate for where they parked and being on Savage-Lundy trail. Exposure vs. lightning vs. familicide..doubt gases or harmful algal bloom. I could be wrong af, and usually am.

https://www.sfchronicle.com/bayarea/article/Not-one-clue-The-mystery-is-only-deepening-16401921.php

https://www.google.com/maps/@37.6051229,-119.8336832,15z?hl=en

^^  Stymied by a paywall. Does look like that section of the South Fork could become separated into relatively stagnant pools in a low water situation. Prime for cyano-bacteria. It’s bound to be pretty darn hot in that hill country.

John can you summarize the article?

It seems impossible that such a young, joyous looking family could commit suicide together. And yet nothing else really makes sense. We’ll know soon enough.

for obx hiker…loop hike about 7.7 miles…image in article but also freely shown on twitter.

08/16 at 11 p.m.- missing persons report came in

08/17 at 2 a.m.- couples truck found on Hites Cove Rd at trailhead (south trailhead of Hites Cove trail); backup called in

08/17 at 3:20 a.m.- sheriff’s office reserved a search helicopter for daybreak. They called in a second search team that began winding down the switchbacks that complete the loop back up to the Forest Service gate. This section of the Hites Cove Trail makes a loop, with the halfway point the south fork of the Merced River.

08/17 at 11 a.m.- about 1.5 miles down the switchbacks the team found the family in the middle of the trail. The husband was in a seated position, the child beside him along with the dog, and the wife just a little farther up the hill. Briese said they believe the family was returning to their truck.

A cell phone was in Gerrish’s pocket. There is little to no cell coverage on that section of trail. Investigators are trying to determine if the phone saved any failed text message drafts, attempted calls or photos, along with GPS location data, Briese said.

The family also had a backpack with a bladder that held a small amount of water, the sheriff said. They sent the water for testing. There was no indication whether the family had been swimming, as they would have dried off by the time they were found, he said.

There are no other obvious signs of trauma or notes indicating troubles. Authorities are investigating deadly gas exposure from unknown mines, toxic bacteria blooms in the waterways and basic dehydration — it was 107 to 109 degrees Sunday afternoon when officials believe they hiked.

Thanks John. You ought to be a journalist. Nicely composed and very thorough.

Looks like any mine sites are on the north side of the river downstream and near Hites Cove.

https://www.fresnobee.com/news/local/article253616898.html

So is there no past evidence or knowledge of algae blooms in those waters? Or is cyanobacteria known to exist there?

Very scary to think there could be no warning, no signs of algae, but enough poison in the water to kill you after drinking 1-2 liters miles after filling up.

Over 100 degrees, they must have been going through a lot of water…

From way down the page of Jacob’s posted article:

“Andy Stahl, executive director of Forest Service Employees for Environmental Ethics, noted that aerial fire retardant (which contains some of those nutrients) is known to trigger algae blooms, and that retardant was used to fight the 2018 Ferguson Fire that burned in the area where the Mariposa family was recently found dead.”

Those of you that have access to Caltopo can look at the boundaries of the Ferguson fire. On the global aerial view, you can see that a large portion of the North x NW facing slope of the ridge that their loop circled and actually most of the area except portions right against a stream or the river, was burned recently.

Probably some other reason but still interesting.

OBX, what I posted is almost all cut and pasted..I forgot to add quotes in my haste to cut down the aritcle.

I have done trail work in that exact area after the fire.  It was burned severely.  I can’t imagine that it would have been a pleasant hike to climb up those switchbacks…not much shade at all.

We did clear the trees off the trail, though…sigh

Yeah, it was 103-109 degrees that day. They were found on unshaded switchbacks, climbing up. Little shade for the whole hike. Hmmmm….

today’s Chronicle says that toxic mine fumes have been ruled out.