Bay water quality/safety for swimming

by norcal, Wednesday, October 31, 2018, 16:06 (14 days ago)

I’m looking for recent, preferably quantitative information about water pollution in ZIhuatanejo Bay. We will be travelling to Zihuatanejo in January regardless of what I learn about this topic, however, we might decide to make reservations somewhere with a big pool and avoid swimming in the ocean.

I’ve looked at the “playas” data on the SEMARNAT website and the numbers don’t look bad, but the most recent data is from March 2018. After reading on this site about sewage discharge into the Bay during Tropical Storm Vicente earlier in October I started wondering how much the Bay actually cleans itself out with regular tidal action.

Does anyone know of any other resources that monitor water quality and pollution in the Bay? If there isn’t any actual testing going on, I suppose I’m still interested in hearing “opinions” about water quality and safety for swimming.

Avatar

Bay water quality/safety for swimming

by Talley Ho @, Wednesday, October 31, 2018, 16:20 (14 days ago) @ norcal

We walk Playa la Ropa each and every morning, swim with our dogs, and paddle our boards most mornings. Although this is not scientific, we are very very aware of water clarity, which is at least an indication of solids in the water.

During rainy season you can watch from up on the hills where the canals and other run off enters the bay. They leave brown rivers as they enter the ocean. During the dry season, this isn't a factor.

In the week since Vicente we have watched the water clarity improve daily. Probably by tomorrow we will have 20 feet of visibility. Yes, really.

We find that the water appears grossest when there are a lot of boats anchored. During Sailfest it can be disgusting with fecal matter and other "stuff" floating on the surface. Many of the boats that anchor off of Playa la Ropa will sit there for a month at a time and not leave the bay to dump. HOWEVER, there are some that are very good about it and don't pollute the bay.

We are in the water at least once a day. Neither of us or the dogs have caught anything. That doesn't mean that it isn't there, but we have not been affected, at least yet.

The monitoring numbers should be available and surely will be posted.

Bay water quality/safety for swimming

by cd69 @, Winnipeg,MB,Canada, Wednesday, October 31, 2018, 16:35 (14 days ago) @ Talley Ho

I frankly would not trust any numbers published as I find the testing done very unreliable at best. The frequency is also a factor. As Talley Ho pointed out, after heavy rains and when lots of boats are in the bay, it can be pretty bad and when it is, you often can see it. In January, it is not common but there has been some very good rains like a few years back when they had 1' of rain in 24 hours and that brought a lot of pollution in the bay and I certainly would not have put my feet in that water. Where you swim will also make a difference as Las Gatas, especially toward the outside part of the beach will tend to stay the clearest. But being a bay with a fair amount of boats staying there in peak season will tend to give you more pollution than open water like Ixtapa. And as much as some people swim every day with no issues, may have had skin problems, especially in rainy season and also in peak season. I would swim in the pool and walk on the beach and enjoy the views...

Bay water quality/safety for swimming

by Casa Juan @, Thursday, November 01, 2018, 07:24 (14 days ago) @ cd69

not a scientist but went swimming on 10/31/18 at far end of La Ropa towards Las Gatas and there was lots of plastic under the water at 3 ft depth and green bubbles on the surface with maybe 3 foot of clarity. The reality is the bay is polluted and some effort towards a sewage plant capacity increase or at least storm water separation for the most heavily populated areas is urgently needed . This is an issue that the chamber of commerce folks should jump on if they care to protect tourism.

Avatar

Bay water quality/safety for swimming

by ZihuaRob ⌂ @, Zihuatanejo, México, Thursday, November 01, 2018, 08:21 (13 days ago) @ Casa Juan

The “green bubbles” are algae and it is normal for this time of year from the warm water and rain runoff. The plastic is also a product of rain runoff but is unfortunately now rivaling marine life for space in all the world’s oceans. The European Union smartly banned single-use plastic. Need more countries to follow suit.

sugar coating re Bay water quality/safety for swimming

by Casa Juan @, Thursday, November 01, 2018, 14:15 (13 days ago) @ ZihuaRob

at the end of the day there is more plastic and other detrius in the Bay than could possibly float in from the ocean. The Bay is still a garbage dump for Zihua and will remain so until the wastewater and storm water situation is given a serious fix involving lots of pesos. I know that this is not what the tourism folks want to talk/hear about but its not going away as long as the seasonal rains fall.

Avatar

the sweet stuff

by ZihuaRob ⌂ @, Zihuatanejo, México, Thursday, November 01, 2018, 16:01 (13 days ago) @ Casa Juan

at the end of the day there is more plastic and other detrius in the Bay than could possibly float in from the ocean. The Bay is still a garbage dump for Zihua and will remain so until the wastewater and storm water situation is given a serious fix involving lots of pesos. I know that this is not what the tourism folks want to talk/hear about but its not going away as long as the seasonal rains fall.

Yeah, you’ve apparently confused me for one of those “tourism folks”.

I don’t have any scientific data. I was born on the banks of the Ohio River. At the age of 3 two neighbor kids and I decided to take our innertubes out to Twelvemile Island. Needless to say, we rather quickly found ourselves heading for The Falls. I grew up in the Caribbean and the Gulf of Mexico and here. Right before I moved here beaches around the world were not just seeing the normal flotsam but incredible quantities of plastic including syringes. Turned out the source of the latter was cruise ships and military vessels, and to a degree that problem has been attended to. We certainly don’t see anything close to the number of syringes on the beaches anymore.

We had very little rain this year. The last one was a minor deluge but certainly enough to wash a lot of plastic into the bay as happens in most modern coastal and waterfront communities around the world. Each of the places I’ve lived has suffered some form of marine degradation. Zihuatanejo has fared the best. The ocean area of the Caribbean I’m familiar with suffered immensely from natural and human factors including hurricanes, bleaching and lion fish. Both the Gold and Sun Coasts as well as Big Bend, the Panhandle, Lake Okeechobe and the Caloosahatchee River of Florida have been devastated by red tides that now last years at a time, blue-green algae and hurricanes. The degradation to Zihuatanejo’s coast in that same timeframe is minimal in comparison. The sickest I ever got from the ocean was the Caribbean. Christiansted Harbor. Terrible double ear infection.

I doubt we’ll ever see the ocean as beautiful as it was during my youth. Time to enjoy what we have left while we can. :vacation:

the sweet stuff

by Casa Juan @, Friday, November 02, 2018, 00:06 (13 days ago) @ ZihuaRob

if the shoe fits ....

Bay water quality/safety for swimming

by Tere @, Thursday, November 01, 2018, 09:01 (13 days ago) @ Casa Juan

I was swimming yesterday also - but in Playa Manzanillo. Same greenish water with poor visibility. Ron's right - it's probably algae and just the ocean adjusting to the change in temperature. I'm out snorkeling at least once a week - either there or at Las Gatas while my husband cleans the bottom of his panga. I wouldn't swim at play principal, but after waiting a day or two after rains, I'd swim anywhere else in the bay.

Avatar

Bay water quality/safety for swimming

by ZihuaRob ⌂ @, Zihuatanejo, México, Wednesday, October 31, 2018, 18:06 (14 days ago) @ norcal

I’m looking for recent, preferably quantitative information about water pollution in ZIhuatanejo Bay. We will be travelling to Zihuatanejo in January regardless of what I learn about this topic, however, we might decide to make reservations somewhere with a big pool and avoid swimming in the ocean.

I’ve looked at the “playas” data on the SEMARNAT website and the numbers don’t look bad, but the most recent data is from March 2018. After reading on this site about sewage discharge into the Bay during Tropical Storm Vicente earlier in October I started wondering how much the Bay actually cleans itself out with regular tidal action.

Does anyone know of any other resources that monitor water quality and pollution in the Bay? If there isn’t any actual testing going on, I suppose I’m still interested in hearing “opinions” about water quality and safety for swimming.

As CD69 commented, there is no reliable testing done of our bay waters. Unless incoming administration changes the protocol, a new report on our bay's alleged enterococcal measurements should come out around the second or third week of December just before the Christmas/New Year vacation period. Because the testing is so infrequent I do not consider it reliable. And because the bay isn't tested for anything other than enterococcal bacteria I also don't consider the testing very helpful.

That said, because I've lived by this body of water for around 30 years, I trust my senses. I know what it smells like, what it looks like and what it sounds like. While there are parts of the bay with problems, including the bottom of the bay which is no longer visible when crossing it by boat. However, with the measures that have been taken over the years at the insistence of good and responsible citizens, I wouldn't hesitate to swim today at Playa La Ropa, Playa La Madera and Playa Las Gatas. And some days Playa Principal should be fine for swimming, too. The pluvial water from the canal has mostly stopped flowing. There is no muddy smell anywhere I've been recently except in the areas with mangroves, as it should be. Only "Las Salinas" lagoon continues having "treated" wastewater discharged into it, though they are trying to use the "brown water" for irrigation purposes, so since the rains have apparently stopped more "brown water" should be diverted to this purpose instead of being discharged into the bay. As far as I'm aware the relatively recent problem at La Ropa's estero was resolved, and the rains opened it up anyway, as they've also done at La Barra de Potosí.

[image]

Avatar

Bay water quality/safety for swimming

by Talley Ho @, Wednesday, October 31, 2018, 19:00 (14 days ago) @ ZihuaRob

:megusta:

Is that a perfect picture of our paradise or what?????

Avatar

Bay water quality/safety for swimming

by juanrojo @, Wednesday, October 31, 2018, 21:45 (14 days ago) @ Talley Ho

At the mention of the Semarnat website I went to have a look. They have a odd prevaccional schedule. The chart has tabs above it that are interactive to change dates displayed. There are June 13th to 18th 2018 numbers available via a tab.

There is nothing earth shattering about the June figures although they are just a bit worse on average than March.

The Playa Principal number, the potential outlier, maybe outliar, was not available for reasons of, eventos meteorologicos adversos which might as well be the dog ate my homework but probably not a big deal.

Overall the assessments mentioned by others would be ours too.


The last few years all have late November test dates. The November testing would be most likely to show rain borne contaminants not adequately flushing but the numbers are consistently good.

--
Please be happy always