• Renee Dolecal, M.S. candidate in Ecology

     

    Renee holding a lobster

    Renee holding a lobster. Photo credit: Renee Dolecal.

    Many marine predators are dependent on their sense of smell to find their food. However, this can prove to be quite challenging if the animals they are preying upon are particularly good at hiding their stench. Prey do not want to be found and eaten and go to great lengths to hide their smell. Because of this, many animals do not become detectable until injured, as damaged tissues “bleed” more potent and distinguishable chemicals that predators often find highly attractive. However, most of the animals that predators eat are not walking around the seafloor like a bunch of zombies with their limbs falling off. So how else can they find prey if they are not stinky or injured? Terrestrial studies have suggested that plants may help predators find their prey. For example, when herbivores (or plant eaters) munch on plants, the plants themselves release chemicals that signal they are under attack. Predatory insects and parasitoids are able to use the plant signals to find their food from a distance. Unfortunately, there are only a few examples of this in the ocean, and it remains poorly understood.

    My research aims at understanding how kelp forest predators, like lobsters, find their herbivorous prey, and whether chemical cues released from seaweeds are important to their hunting strategies. What I have found is that kelp forest predators are not able to use cues released from common seaweeds like giant kelp and sea lettuce to find herbivores munching on their tissues. However, herbivores do become more attractive when injured. Not surprisingly, I have also found that kelp forest predators find bait fish highly attractive. While this may not seem like new information to share with fishermen, it does highlight an important observation about foraging predators. Predators that use their sense of smell to find food and can tell from a distance which food items are more valuable and vulnerable. Fish are a rarely encountered and valuable food source, while injured herbivores are a vulnerable type of “fast food.” This is important to understand because we often assume that live prey are the most important food items in predator diets. This may not always be the case, as live herbivores are not easily found relative to other more attractive cues like crushed urchins and dead sardines.

    A little about me

    Like many marine biologists, my love of the ocean began when I was young, spending lots of time on the beaches of Long Island, NY. However, it was during my undergraduate years at Northeastern University that I discovered my desire to become a scientist, by participating in a field intensive study abroad program called Three Seas. Through this program I traveled across the world to study rocky intertidal, coral reef, and kelp forest ecosystems. It was here that I was exposed to the rigors of science, the excitement of discovery, and satisfaction of conducting independent research. Shortly after completing this program, I completed my B.S. degree in Biology with a concentration in Marine Biology, and began work as a research assistant, working with several prominent marine ecologists at Northeastern University’s Marine Science Center. After deciding that I wanted to continue marine ecology as a career, I joined Dr. Jeremy Long’s lab here at SDSU and am currently working towards completing a Master’s degree in Ecology.

     

    Renee collects kelp in the field

    Renee collects kelp in the field. Photo credit: Renee Dolecal.

    My research interests

    I find myself constantly inspired by different ideas, and have many broad interests as they pertain to community ecology in marine ecosystems. More specifically, I enjoy studying chemical ecology, investigating how chemical cues affect species interactions and community structure. For my master’s thesis, I am looking at the chemical cues released by seaweeds when eaten by herbivores, and how they influence predator foraging. Scientists on land have long studied this type if interaction between plants and arthropod insects, but we still have a poor understanding of how common this is in the ocean. The goal of my research is to help shed light on these poorly understood interactions to learn how predators find their prey, and gain a more broad appreciation for how chemicals influence marine community structure.

     

    A typical day in the life…

    More like a typical night in the life. Most of my research has to be done at night because I study benthic predators, like lobsters, which actively forage after dark. During the day I spend my time preparing for field experiments and entering data, but at night is where the fun begins where I collect my data and observe predator behavior. What are the perks of being a night owl? Some of the coolest things happen at night when the rest of the world is sleeping – incredible glowing water created by bioluminescent phytoplankton blooms, and daily Sea World fireworks displays lighting up the summer night sky.

     

    Renee measuring a lobster during night sampling

    Renee measuring a lobster during night sampling. Photo credit: Renee Dolecal.

    Why is being a biologist awesome?

    I love being a marine biologist because I feel like I am able to see and experience so many cool places and things that most people will never experience in their lifetime. It’s amazing to get to study such an extraordinary world under the sea that we have just barely begun to understand. The opportunities of exploration and discovery seem endless, and I am always excited by anything new I learn about it.

     

    Fun project facts

    • Believe it or not, the study of how plants attract predators has a practical application – biological pest control. Terrestrial ecologists have long studied how plants attract predatory insects to figure out natural ways to control herbivorous pests from destroying important crops like corn, tobacco, tomatoes, and legumes.
    • Seabirds and penguins can use cues coming from phytoplankton blooms to find herbivorous prey like krill and small fish from 100’s of kilometers away!
    • The idea that predators can use plants to find their food has also been referred to as the “bodyguard hypothesis.” As predators remove or parasitize herbivores eating plants, they alleviate the amount of damage caused by herbivore grazing, allowing the plant to survive.

     

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