Dan Castellanos

Biologist, M/V Spree

Expedition Role: Dan Castellanos uses scuba gear to complete several dives in the coral reef zone of the Flower Garden Banks National Marine Sanctuary. He will help to change the batteries and gather data from the three acoustic receivers in the sanctuary. He will also help to set up more receivers and tag more manta rays. 

On Your Career…

What do you do for a living?
There is no one thing that I could do all year, so I do many different things. I do commercial fishing for lobster, conch, and fish. I do tour-guiding and sailing. I also do research with Rachel Graham and other folks.

How did you end up doing what you do today?
I started out as a fisherman. One of my colleagues was working with Rachel and other researchers. They were looking for a boat captain. I found out about the opportunity and started working with the researchers as a captain. With the experience that I had from fishing, I could answer a lot of questions about what they wanted to know. Then they came up with enough funding for me to start diving along with them. I saw a lot of things that I hadn’t seen before. It was a whole new world. There was so much that I didn’t know, but I kept learning new things. Every day that I went out do field work, I learned something new.

How and where do you conduct your work?
The majority of work that I do is in Belize and at the Flower Garden Banks National Marine Sanctuary (FGBNMS). Next year we are starting up a research project in Honduras—in the Bay Islands. We might also do some work in Mexico. Another place that I hope to get to at some point is Madagascar.

What tools and/or technologies do you use in your work?
We use satellite tags for the whale shark research. For the manta rays, we use acoustic tags and acoustic receivers that we moor at the bottom of the reefs. We are planning to use satellite tags with the manta rays in the future.

What do you like the best about your job?
What I really like about what I do is that I am learning something new every day about a species that nobody has really studied before. I am learning how manta rays behave, where they go, and how they live. It’s really exciting!

Where’s your favorite place that you’ve been to so far?
My favorite place is the Flower Garden Banks. The coral coverage and the fish are amazing. I have never seen anything like it before—everything is just covered with live coral. It’s really beautiful. It’s one of the only places to see coral spawning like that, too.

What do you like the least about your job?
What I like the least is that research doesn’t always work. Sometimes, with what we do in Belize, we look for sharks and we don’t find any. There are very few sharks left, and we have to do something about it. The sharks have been fished heavily. We know that this is happening and we are trying to make it so that whale sharks are protected. I used to fish sharks, but I haven’t done it for over eight years. Since I have been working with researchers I have seen what is going on. While I was fishing sharks, you could see that the numbers were going down, but it’s nothing like what we’re seeing now. We know what needs to happen, but it’s hard for some of these shark fishermen to change.

What is the most incredible thing that has happened to you while conducting your work?
One time I was diving along with a school of spawning fish. I was using an underwater video camera to film the fish. The water was really cloudy because of all of the fish spawn. As I was filming, two bull sharks came out of the school of fish and headed straight for me. Bull sharks are beautiful, huge sharks. I was excited and scared at the same time. Luckily, they just swam by me and went away. I used to be very scared of sharks. Now I dive with sharks all the time. It is so amazing to watch them swim around. They’re worth so much more alive than dead.

What advice would you give to kids who are interested in studying science?
I would really encourage a kid who wants to get into marine science to do it. There is so much more to discover about what is out there. I’m hoping that new technologies might make studies possible in even deeper water.

On the Expedition…

What is your role on this expedition?
One of my primary jobs is tagging the mantas. I will also be taking up the acoustic receivers, bringing them back to the boat, and downloading information to see whether there are mantas crossing from one bank to the next. There would be a lot more that I could do, but I need to watch the mantas and be ready at all times. They’re pretty fast! I’ll be diving most of the time in mid-water—not too shallow and not too deep. When I see a manta, I swim with the dart and then tag the manta. Sometimes we wait for hours to see a manta. Sometimes we see one almost every dive or we see two or three in the same dive. Other times we don’t see any. When we finish a dive, sometimes the mantas come right by the boat. Then I jump in the water and use a mask and snorkel to swim with them.

What one thing would you most like kids to learn from the Secrets of the Gulf expedition?
I would like them to learn more about the behavior of the manta rays—where the mantas move, how they move, and how deep they dive. I would also like them to know that mantas eat plankton and are very playful. There’s no need to be scared of manta rays or their size. They’re very friendly.

What about the expedition is most exciting to you?
What I’m really excited about is that there’s not much known about manta rays. We’ll probably find out a lot about how the mantas move from one bank to the next. We can find out how long it takes for them to travel between the banks. In the future, when we use satellite tags, we’ll find out how deep the mantas dive. Nobody knows that much about the diving behavior of mantas. We also might be putting more receivers out down the road. We are thinking about putting some receivers on oil and gas platforms.

On Being a Kid…

What did you like best about school?
I didn’t like school. The reason I didn’t like it is that I was so into fish. I wanted to be out fishing or out seeing fish all of the time. It was my favorite thing. I was really unhappy when that was taken away from me. As soon as I got out of school, I would go along the coastline to play in the water and fish. I realize now that school could have been really good. I would tell kids now to go to school first and then do all the fishing they want.

What advice do you wish that someone had given you when you were a kid?
I wish someone would have told me to finish school. In Belize, not everybody needs a high school degree, and I became a fisherman right after primary school. My dad is a fisherman, and most of the stuff that I know I learned from him and my older brother. From the time I was really little, I knew that I would be a fisherman. I didn’t know that I would get involved with research until I started to do it. Then I found out that I really like it.

On the Rest of Life…

Who are some of the people you look up to or admire?
One person I really admire is my dad. He taught me a lot about the sea and really encouraged me and pushed me to get into the research. Another person is Rachel—she has taught me a lot. One of my colleagues, Eloy Cuevas, has also taught me a lot and has encouraged me to continue with research.

When you are not working, what do you like to do for fun?
I love to go out with my friends and play soccer. I have known my friends for a long time and we just have a good time. While I’m hanging out with my friends, I explain a lot about what I do. I try to get more of my friends and other fishermen involved in conserving and protecting sharks. When people understand, they are less likely to dive or fish in marine protected areas.

Do you have any final thoughts or words of advice that you would like to share?
For whatever you decide to do—marine biology work or whatever else—make sure that it is something that you really love. There’s nothing worse than doing something that you don’t like doing. If you do choose marine biology, you have to be really excited and very patient. Sometimes you don’t get what you’re expecting the first time, so you have to be ready to do it again.

JASON Learning: A Partnership of Sea Research Foundation and National Geographic