diving visability over the last 200 years or so

[scubamama5]

Drewski and Crowley's posts are right on.

to borrow from Crowley:
"Best solution: stop putting crap in the ocean that doesn't belong there and stop taking out the stuff that does!"


(did write a bunch... but lost all I wrote... tryin to quote)

Can spare Ya'll now...just don't have it in me to rewrite....

So?....How long do ya think it will be to clean up the GulfCoast now?

 

[Walter]

I dunno about visibility, but even a few decades ago there were a lot more fish ... and the big ones were a lot more common.

... Bob (Grateful Diver)

Maybe, but I see as many fish now as I did 20 years ago and more big ones. Twenty years ago Jewfish were rare. Now they are common in many areas. Twenty years ago, I rarely saw sharks, those few I did see were Nurses. Now I see lots of sharks of different species. I don't see as many Hogfish today and I see lots fewer lobster.

 

[captndale]

I haven't noticed any change in the visibility of ocean waters in the 37 years I have been diving but the change in local waters has been nothing less than amazing.

Much local diving is done in quarries, gravel pits and open mines that have ceased production. The visibility in these bodies of water tends to be very good when they are new. Over the years, as they accumulate silt, run off and the like they gradually lose visibility. Most small natural lakes do not exhibit any discernable change oveer such a small time span as an individual diver's career.

There has, however, been an abrupt change in the visibility of the Great Lakes. In Lake Michigan, my playground, as recently as the late 1980's the average visibility was 3 to 10 feet. A dive with a visibility of 20 feet would be talked about with reverence for months afterwards. Now, our average visibility is 40 to 50 feet, and 100+ feet is not unusual. The difference has been the introduction of invasive speciess of small mussels. The filter feeders clean up the organic particulate in the water. The downside, from the divers' perspective, is that the mussels attach to every hard surface and obscure the surface features of the shipwrecks.

 

[seaducer]

Maybe, but I see as many fish now as I did 20 years ago and more big ones. Twenty years ago Jewfish were rare. Now they are common in many areas. Twenty years ago, I rarely saw sharks, those few I did see were Nurses. Now I see lots of sharks of different species. I don't see as many Hogfish today and I see lots fewer lobster.

I was going to say something similar. It really depends on where you are and what species you are talking about. In some areas conservation efforts have improved. In decades past it was common for people to fill truck beds with bluefish and striped bass, in the 80's it was rare to catch either species at times. Now they are making a comeback with strict catch limits.

Some fish are also cyclical, but any dips in population are quite possibly our fault anyway, since most people look at fish as natural resources ripe for the money they can demand for them.

As far as visibility goes, I am not sure many places would be much different, though some certainly would be. I am sure the Hudson River was clear at some point, but perhaps Raritan Bay was always silted out...

 

[JohnB47]

From 1983-85, I lived aboard a small sailboat (Nor'Sea 27) in Solomons, Maryland. I used to sail all over the Chesapeake Bay. I remember that during one trip to the Hampton Roads area I noticed that the color of the water was a pretty bluish-green. I even saw dolphins swimming in the bay. Now Hampton Roads is usually pretty much brown, although it gets a little bit greenish brown when there is no rain for a couple of weeks.

 

[Herk_Man]

I have been going to Dale Hollow Lake in Tennessee since I was a kid. It's a manmade lake created by the TVA and it has almost no population on the shores, which are primarily shale. The banks are very steep, about 45 degrees, and as a kid on a 60' houseboat I can remember how awesome it was to be able to see the bottom from the back of the boat.

Here's the kicker. About 15 years or so ago they started mandating that all houseboats have holding tanks. Within a year the visibility of the lake DECREASED dramatically. Turns out that the chemicals that were being used to counteract the fact that human waste was being dumped in the lake, was keeping the water clear by denying plant life to grow.

Such irony. We took the poo out of the water and it got murky.

 

[Hank49]

I've always dreamed about going back a couple hundred years. Imagine the uncrowded surf breaks all along the coastlines. And the fish...so much fish. Never mind scuba gear. just take a mask, fins, wetsuit and a speargun...with a floatline.
I'm sure the vis was better before all agricultural runoff, sewage, garbage, roads, tilled lands, coastal development. Imagine what the Gulf must have been like when the Mississippi was still clean.

 

[SDE Dennis]

I read stories that RI had so many fish all you needed was to cast a net into the water to catch them. Also the lobster walked alond the shores at night. Even just having a mask back then would have been great.

It is a shame what we did below and above the water, boy are we stupid. Give a species enough rope!

 

[drbill]

Before the 1970's Catalina was used as a cattle, sheep and goat ranch. Due to intensive overgrazing, there was substantial erosion which undoubtedly affected nearshore visibility here. With the formation of the Catalina Conservancy in 1972 and its acquisition of 88% of the island in 1975, these practices stopped. The removal of feral pigs and goats, vegetative cover increased and such erosion was reduced. Of course there is always a fair degree of erosion off steep terrains in arid climates.

Recently the invasion by Sargassum horneri (= filicinum), a noxious weedy alga from Asia, the visibility has declined through much of the late fall through late spring due to reproductive and decay products released by the darned alga!

 

[drbill]

The accounts of Columbus indicate that turtles in the Caribbean were so dense that you could practically walk to shore on their backs. If only we had good scientific baselines from the pre-Columbian era to judge current ecosystems by.