First Marine Mammals of the Season

 5/25

Dear class,


Our big boat day was met with anticipation from the whole class. Meclizine was taken the night before and the morning of to prepare for a day of sea sickness as we rode out to our site where we would be helping CEDO to survey the sea lion populaton at the Isla de San Jorge. After an hour or two of riding out to the island, we were given papers for each of us to record separate sects of the population. I think our group had it the easiest as we just had to identify the adult males who have a very distinct “casi melon” or a lump on the top of their head. We drifted slowly around the island and ended up counting 47 of them. For some context of the sea lions, they are in the marine mammal pinnipeds group meaning flippered or finned. Something I discovered about this animal is that they can hold their breath for 6-20 minutes as they have an adaptive respiratory system that concentrates their oxygenated blood into their heart instead of extraneous muscles. The males that we saw today are helping to establish their breeding ground between May-July and will fast during this time to protect their harem (group of females) and territory. 


Before today I had always been scared of sea lions because growing up on the coast of California tourists were always getting bit because they would venture too close to the pack. In La Jolla, I had to cross a beach at night and two massive male sea lions were sleeping rather peacefully until I set foot on the beach. One lifted his head and almost tilted it 180 degree at me and let out a bark that made my stomach drop. I knew that if he came for me I’d have to book it to get to safety. Surprisingly we were all met with very different responses from these packs of sea lions on the island, or maybe we were just lucky enough to interact with the more genial females. After floating around for a couple minutes with our snorkeling gear we were greeted by a pack of friendly females who swam around us spinning and showing off. Some showed us their flippers above water to wave at us and one even looked like she was doing a headstand for us so that her hind flippers were above the water. Though one male became unhappy with us swimming too close to his pack, the rest of them seemed intrigued that we were there. The visibility in the water was low and I didn’t have my contacts with me so I couldn’t see extremely clearly but it was still amazing to be able to be so close to these animals in their home. My perspective on these “angels of the sea” has changed for the better after today’s excursion. 



Comments

Post a Comment

Popular posts from this blog

First Day!

Image
We arrived at CEDO yesterday midday and spent the afternoon getting settled in our new home for the week.  In the late afternoon, the students learned about oceanography and all of the different types of invertebrates we will encounter throughout the week. We ventured downtown in the evening and ate at a restaurant with a scenic view.  When we got back to CEDO, it was close to low tide so we ventured down to the shore to do some night tidepooling.  The students are excited for the real fun to begin tomorrow. We are planning to do more tidepooling near CEDO in the morning, and have a CEDO biologist giving a lecture on the natural history of Puerto Penasco in the afternoon. We hope to finish up our lecture material today so that we can spend the rest of the week focused on our field work--tidepooling at rocky and sandy habitats, kayaking an estuary, and taking a boat trip to a sea lion rookery! -Whitney
Read more

5/23/2024 Tide Pools (Oliver Pheil)

Image
      After our first stay for the week at Puerto Penasco, we began our first try at looking at different ranges and types of organisms at the tide pools directly next to CEDO. During those three hours of walking over the rocky flats while trying not to trample and fall over them, we came across many different kinds of invertebrate species. The most notable one that everyone could think of on the top of their heads was a turbellarian flatworm, a type of flatworm that is under the category of Phylum Cnidaria. The reason why this was an interesting find is because of the way they swim by using rhythmic muscle contractions, making them have a ribbon-like movement. While I didn't find this, I did find a few other organisms under a few rocks hidden underneath: a sea urchin, and a few small sponges. 
Read more

Interesting Crab lovers in the Sea of Cortez

Image
   So to start off I have been to Puerto Penasco, Mexico many many times and I honestly did not know about how diverse the marine life was here. I have seen baby turtles being released before, so I at least know that turtles inhabit these waters. However, typically the only time I would see marine life was either a dead fish washed up on shore or in someones taco. Thankfully this trip has been expanding my knowledge on the marine life h ere and I saw a very interesting find on my very first night at CEDO which is the intercultural Center for the Study of Deserts and Oceans. While on our search for marine life during low tide during the night we found these crabs as seen in the picture that are in a mating embrace, where the male crab will wrap himself around the female so that she cannot escape. Nothing to crazy right just crabs mating, however what made this interesting was that they are both females. We observed based on the shape of the apron the underside of the crabs that they wer
Read more