Stalking the Grey Ghost

Bonefish, AKA the “Grey Ghost,” are powerful, fast and highly prized by flats-fishermen in South Florida’s coastal waters. But they are disappearing. Fortunately, scientists and fishing guides are banding together to save these amazing predatory fish.

An “otolith” is

South Florida is often called the “sport-fishing capitol of the world

Because of the shape of their fins, bonefish

In 2015, Florida Bay experienced

As we learned, healthy coral reefs are full of many different species of marine life. They’re like the “cities of the seas,” in part because corals create stony structures that offer shelter and attachment points for things like small fish and invertebrates.

Can you think of other, non-marine habitats that are also very biodiverse? What do these habitats have in common?

Stalking the Grey Ghost

South Florida is the undisputed sport fishing capital of the world. With its warm climate and rich ecosystems like the Everglades, many species of hard-hitting sport fish call this place home. And for the same reasons, anglers from all over the world travel here to cast a line in the subtropical waters. For many, the grey ghost is the ultimate catch.

These fish are really built for short and fast bursts of speed, which really makes them an incredible fish to fight and catch and is one of the really big draws for the fish, just this incredible power and energy that they have, it’s unlike anything else.

As with any animal, bonefish rely on healthy habitat to thrive. Historically, Florida Bay contained world-class bonefish habitat with some of the most expansive and vibrant seagrass beds on the planet. But things have changed.

So bonefishing in the park has changed dramatically over 15 years. … the most obvious change is their range, and the range is directly proportionate to the amount of grass in the habitat that’s available.

In the late 1980’s, Florida Bay was rocked by a massive seagrass die-off. This event was triggered by a drought and hypersaline conditions….the effects of restricted fresh-water input from the Everglades. In a nutshell, Florida Bay, in its natural condition, should be a brackish estuary that is nourished by fresh-water sheet-flow from the Everglades. But over 100 years ago, the process of draining the Glades begun through a vast network of canals. Today, the so called “River of Grass” is a shadow of what it used to be, and estuaries that rely on its waters suffer. Not surprisingly, as the habitat goes, so do the fish.

For bonefish populations to be thriving, there has to be a lot of elements to the ecosystem that has to be thriving too. They need good water quality so they can have the appropriate air to breathe, they also need the right amount of food and the right amount of shelter from predators. And if any of those things get disrupted, than the bonefish populations will go down.

Bonefish in South Florida have been in a decline and as far as we can tell that decline dates back to 1980, in particular we see that the numbers of bonefish are much lower post-1999 and late 1990’s.

The seagrass die-off of the late 80’s was a catastrophe. But just as is seemed that the Bay was on the road to recovery….

So in 2015 we had the perfect storm. We had no rain. And without the rain and the natural sheet-flow from Lake Okeechobee that we would normally get this side of the Everglades, we had an influx of saltwater in the park. … in 2015 we lost between 40,000 and 50,000 acres of grass in Florida Bay.

As Florida Bay clings to life by a thread, biologists are beginning to look at other places where bonefish populations are stable. In Las Salinas on Cuba’s southwest coast, bonefish and their habitat seem to be thriving.

I think that as we consider what’s happening to bonefish in terms of decline and sort of slow recovery, it’s super important to think about reference points, and try to keep in mind that bonefish occur in South Florida within this matrix of anthropogenic impacts on multiple scales, impacted by the hydrology and altered coastline and all kinds of things associated with that. And it’s really nice for us to sort of zoom back out and go to these intact wetlands where the hydrology is unaltered.

Las Salinas represents an ecosystem that is relatively unaltered, where human impacts are at a minimum. For biologists like Dr. Rehage from Florida International University and Dr. Boucek from the Bonefish and Tarpon Trust, Las Salinas may prove to be an important reference point; an example of an estuarine habitat that is healthy and functioning near its full potential.

Back in South Florida, Dr. Rehage and her team, along with Dr. Boucek are taking a hard look at bonefish populations in Florida Bay. One of the big mysteries they are trying to solve is: what habitats are baby bonefish utilizing, and what are their environmental requirements?

So all science has a glamorous side and a non glamorous side. …. And seining is not glamorous.

We’re pulling nets in places where you would not think there would be bonefish. We’re running our nets through these muddy, hot places, very little seagrass, in places in the Everglades where we thought there would be no bonefish and yet, we’re finding bonefish which has been really rewarding.

Finding juveniles of this size is incredibly rare. As remarkable are the areas that Dr. Rehage has been finding them: coastal bights and small bays that, under natural conditions, would have a high input of freshwater flowing from the Everglades. These areas were also hardest hit during the 2015 seagrass die-offs in Florida Bay when freshwater input trickled to a halt during the heat of the summer.

Back in the lab, the team has had another revelation by analyzing, of all things, a small calcium carbonate structure called an “otolith.”

The otolith is the ear-bone of fish. They’re used for balance and for hearing, but they also grow in rings and they are a hard substance. Because they are a hard substance that’s always present in the fish, it provides and it’s absorbing chemical information about the chemical environment that fish experience and they provide a record about the entire chemistry of fish as they grow.

The chemical analyses of otoliths has lead us to learn that some of the bonefish, the majority that we’ve analyzed are using low-salinity environments early in their life-history. What does that mean? That means that some of these babies of bonefish are spending time in estuarine waters. Low salinity environments.

This finding has potential implications for the importance of Everglades restoration. In other words, restoring freshwater flow to the estuaries of Florida Bay might be the right formula for a healthy bonefish nursery. For the past few years, this is exactly what flats guide Benny Blanco has been fighting for.

So for me a perfect day in Florida Bay is when we have a light Northeast wind, combined with an outgoing tide on the west side of the bay because it lends itself to cleaner water situation. And everyone comes here to sight fish. No one comes here to blind cast in the mud.

I’m fully connected to Florida Bay in the sense that when I was a kid, I found myself here. It’s where I come when I need to reconnect, it’s where I come when I need to get away from the planet, and I’ve been fishing in Florida Bay for 30 years, been guiding for 20, since 1998, and the last 10 years I’ve been full time, 280-300 days a year. So the health of the bay is critical to me personally, emotionally, but it’s also critical to my business and livelihood and how I feed my family.

There’s a great part of me that understands that if we’re ever going to have an existence on this planet as a race, we have to leave places like this better than we found them.

Coming soon


The Florida Scrub Jay

Gopher Tortoise: Ecosystem Engineer