Have you ever come across a strange peculiar object that looks like a dried out husk along the beach? Believe it or not, they’re not driftwood or anything plant related, but are egg cases!
Archive for the ‘Cool Creatures’ Category
When people think of sharks, they think of the majestic White (Carcharodon carcharias), the sleek Blue (Prionace glauca), or the fast Shortfin mako (Isurus oxyrinchus).
What is a Ray?
However, many people do not know that sharks have other relatives. Elasmobranchs refers to fishes that have a cartilaginous skeleton, no swim bladders, and have five to seven gill slits. We will be focusing on the batoids, aka ‘flatsharks’. People might be familiar with the word ‘ray’, but what defines a ray? A ray is a flattened shark, with the gill slits only visible on the ventral side. Currently, there are six orders of elasmobranchs taxanomists have defined as batoids. They include: Pristiformes (Sawfishes), Rhiniformes (Wedgefishes), Rhinobatiformes (Guitarfishes), Torpediniformes (Electric Rays), Myliobatiformes (Stingrays), and the Rajiformes (Skates).
Here are what some of these batoids look like:
As you can see even these flat sharks are variable in morphology! If you are interested in how these orders are related in-depth, please check out the Tree of Life! We will go through all these different orders at a later time, but let’s focus on two orders: Myliobatiformes (Stingrays), and the Rajiformes (Skates). People often confuse these two groups, since they have similar body plans, but let’s take a closer look at their differences.
It was just announced a couple months ago that researchers in New Zealand found a specimen of the hydroid Protulophila that was previously believed to be extinct for 4 million years. Before this discovery, these organisms had only been found in fossil records in the Middle East and Europe, some of which dated back 170 million years.
Awesome discovery, right? But to take a step back now, what exactly is a hydroid?
Like the previous post mentioned, I went on a 10 day sea voyage with NOAA’s FRAMD (Fishery Resource Analysis and Monitoring Division) survey. This is annual survey that NOAA conducts during the summer to look at the fish community, by taking measurements of weights, lengths, sex of the fish, as well as selecting individuals to extract their otoliths. Otoliths are used to determine the age of bony fish. In many species rings are formed in the ear bones of the fishes. Biologists extract the ear bones from these fish and read them. There are three sets of ear bones, we use the largest set the sagittae. The information then will be used for fish stock assessments.
It is amazing how many different ways organisms can survive in the ocean. One of the most interesting is the many different strategies to try to get food from the water (filled with phytoplankton, zooplankton and detritus (particles of decaying algae and animal material)), from larger algae growing on the bottom, or from the organisms that consume these sources.
We see Kelp Rockfish associating with, surprise…kelp! They eat different crustaceans on the kelp and even eat small year-old rockfish.
This Fish-eating Anemone eats crustaceans and fishes. It would not be pleasant to be captured by one of these and digested slowly!
This Sunflower Star is a surprisingly fast moving predator in the kelp forest. They, like other seastars, extrude their stomach and digest their prey using acids, another not-so-fun way to be eaten.
This beautiful Kelp Greenling male eats different invertebrates and even fishes when they become available.
This lined chiton moves along the bottom scraping the surface, getting foods like coralline algae, detritus (decaying algal and animal material), attached invertebrates, diatoms (algae), red algae, and green algae.
These species are just a preview of what we see each dive around the Monterey Bay area. I am grateful people before us have studied these organisms so we are able to construct food webs to try to understand how all of this diversity we see interacts over time and space.
By Marilyn Cruickshank
With a vast habitat like the ocean, unusual encounters might happen all the time, but our chances of observing them are pretty slim. Last week, the naturalists of Monterey Bay Whale Watch had such a chance, when they spotted a pod of killer whales harassing a juvenile blue whale.
Credit: Monterey Bay Whale Watch
While the interaction didn’t last long, it was clear that members of the pod were rushing the rolling rorqual (baleen whale), as it flung its fluke (tail) into the air. Killer whales, which are actually large dolphins, exhibit similar behavior when they hunt gray whale calves. According to Monterey Bay Whale Watch, such an encounter with a blue whale has never before been recorded in California.
Most of the attack occurred underwater, before the larger whale retreated. It surfaced a quarter of a mile, and then a half a mile away from the killer whale pod, apparently deciding that any food gotten in that area was not worth the hassle. Since even juvenile blue whales can be 50 feet long or more, it is unlikely the pod could have done it serious damage or gotten any nutritional benefit. However, blood was spotted on its fluke, which shows that the interaction was not playful.
While we can only speculate about the reasons for bothering the blue whale, one such might be to practice hunting maneuvers specific to that pod, or to teach younger pod members the ropes. More such encounters would have to be observed before any scientific conclusions could be drawn, but even one helps us learn a little bit more about these amazing creatures.
When we see killer whales doing such things, it’s tempting to think of them as bullies, since they seem to gain no nutritional benefits. However, it is important to remember that such activities help to strengthen social ties within the pod, and that killer whales are wild animals that can’t just go to Safeway if they don’t find food that day. The killer whales are simply doing what they do best- working together to hone their skills as predators in a harsh ocean environment. Even still, it’s good to know that the blue whale got away with little harm, ready to eat tons of krill another day.
If you want to see these and other marine mammal and birds in their natural habitat, you can go to Monterey Bay Whale Watch for more information.
All photos were from Daniel Bianchetta from the Monterey Bay Whale Watch.
by Catarina Pien, PSRC Lab
If you’ve ever visited our lab, you’ve seen the beautiful waters surrounding us, often bobbing with a variety of marine mammals. The main body of water that surrounds Moss Landing Marine Laboratories is Elkhorn Slough, which is an estuarine embayment that drains into the Monterey Bay.
Elkhorn Slough has evolved greatly in the past few centuries. Since the dredging of Moss Landing Harbor in 1946, the slough has become directly connected and thus heavily influenced by the Monterey Bay. This connection has led the slough to change from a freshwater-influenced estuary to a predominantly saltwater-influenced and erosional body of water. A great deal of research has been done to study how these changes have influenced habitat structure and biological communities in the slough.
My own thesis research will focus on Elkhorn Slough, and how various oceanographic variables have changed and are influencing elasmobranch (shark and ray) populations in the slough. I am hoping that the class will be beneficial in showing me how to measure chemical variables, and analyze values in terms of how they influence biological communities.
Last week, our chemical oceanography class was split into five groups and deployed to various water bodies around our school to take some measurements and water samples. It had just rained earlier that week, so we were hoping there would be some visible differences in salinity and nutrient content in the regions we were sampling. Although the main channel of Elkhorn Slough is heavily influenced by the Monterey Bay, and thus oceanographically similar to the ocean, the upper reaches of the slough are often less saline (depending on the season), and more influenced by precipitation. One group went offshore to Monterey Bay, two groups went into Elkhorn Slough, one drove around to Salinas River, Carneros Creek, and other connected sloughs, and my group sampled in Moss Landing Harbor.
We took one of our school’s whalers on a beautiful sunny morning, excited (though some of our facial expressions may not be representative) and ready to sample.
We motored slowly through the harbor, observing sea lions sunning themselves, and being observed by harbor seals and a portly sea otter.
Once at a station, we used the CTD (Conductivity Temperature Depth) to measure salinity, temperature, and pH at eight stations within our region.
We also recorded GPS coordinates, and collected water samples with a syringe, and filtered them into a bottle to bring back to the lab.
Many of the changes to Elkhorn Slough have been anthropogenic, including the construction of levees, dikes, tide gates, salt ponds, and railroads. Some of these were constructed early on for agriculture and ranching, whereas others have been created to remedy erosional problems we have created. These barriers have altered tidal flow within Elkhorn Slough, and created distinct oceanographic areas. In order to determine differences between these areas, some stations required us to leave the boat to sample adjacent areas that were separated by a barrier.
We passed by the lab, hoped we wouldn’t embarrass ourselves in front of the whole lab, and successfully finished our collections near the tide gate leading to the Old Salinas River.
Combined with the rest of the teams, we now have oceanographic measurements and water samples all around Elkhorn Slough and the surrounding bodies of water. Over the course of the semester, we will learn how to measure phosphate, nitrite/ nitrate, oxygen, silicate, and alkalinity of the water samples. The measurements will tell us something about how how the stations differ from each other, how Elkhorn Slough is partitioned, and the outside influences to each station.
As marine scientists, many of us spend a substantial chunk of time in the field. While field work can be frustrating and tiring, on a beautiful day like this, encountering a multitude of wildlife and puttering slowly through the beautiful waters, it is easy to remember why we went into the field of marine science.
On Sunday 22nd of December, I had the opportunity to participate with the Marine Mammal Center and help move a Risso dolphin (Grampus griseus ) carcass at Breakwater Cove. Risso dolphins are distinguished by their bulbous head and white body which are heavily scarred from teeth raking between dolphins, as well as markings from their prey such as squid. They are a common species of dolphin found here in Monterey.
This particular individual was found washed up near Monterey and took more than 12 people to move this animal onshore away from the waves. We had to set tarps to make it easier to move it. Risso dolphins weigh around 600 to 1,000 pounds and can reach a length of around 13 feet, making them one of the larger dolphins.
However, the area where we planned to move the dolphin was too steep and we lacked the manpower or the equipment to move the animal smoothly to the truck. So while we waited in the warm sunny weather on what to do next, we tethered the dolphin with rope to prevent the waves from dragging the dolphin back to sea.
So after waiting for an hour, we decided to have the harbor master tow the dolphin back into the water and transport to place to pick the dolphin up with a forklift. Took us two tries to push the dolphin back into the water. The first attempt the rope broke from the stress. Also timing of the waves were not in our favor most of the time, so we have to wait till the perfect wave came to push the carcass back into the water. Overall, I had fun! Never thought I would be able to see a Risso up close and personal! Necropsy will be conducted soon, so hopefully we’ll figure out what was the cause of death.
By Melissa Nehmens
This time of year offers the chance to provide a romanticized explanation of autumn on the central coast. I could explain how here at Moss Landing the weather is turning colder, the leaves are changing color, and the storm clouds bring a scented promise of the rains to come. However, we have more important things to discuss: Halloween!
This past weekend was Moss Landing Marine Labs’ annual Halloween Party. Everyone came in costumes and as part of the tradition, each lab or group brought their pumpkin to be judged by the student body in the pumpkin carving contest. Though officially there was only one winner, I think everyone did a great job. What do you think?