:)
It is 5 millimetres long. To this brittle star, the one little piece of algae I am holding in my hand is a forest.Sunday, August 28, 2011
The things you find in algae, part 2
Sometimes when it is 11pm and I am still in the lab and I have been sorting algae for 8 hours, I need something to remind me why I love marine science. Sometimes that thing is an itty bitty brittle star.
:)
It is 5 millimetres long. To this brittle star, the one little piece of algae I am holding in my hand is a forest.
:)
It is 5 millimetres long. To this brittle star, the one little piece of algae I am holding in my hand is a forest.
Friday, August 26, 2011
The things you find in algae
My big herbivory experiment is done, and the summer is coming to a close - classes start in less than two weeks! There's still plenty that needs to get done - yesterday we did a trip down to Connecticut and Rhode Island to collect some algae. Similar to what I was doing at the start of the summer, we are trying to quantify the species composition of algal communities in different locations, where the invader is present.
So I am back to sorting algae out of bags, which is long and somewhat mind-numbing, but there are many happy distractions in the form of little critters hiding out in the algae.
Today is arthropod day...
A little spider crab sitting on the tip of my finger.
Itty bitty little crab - it looks like an Asian Shore Crab, which is also invasive to this region. For scale: it is sitting on a microscope slide.
So I am back to sorting algae out of bags, which is long and somewhat mind-numbing, but there are many happy distractions in the form of little critters hiding out in the algae.
Today is arthropod day...
A little spider crab sitting on the tip of my finger.
Itty bitty little crab - it looks like an Asian Shore Crab, which is also invasive to this region. For scale: it is sitting on a microscope slide.
Tuesday, August 23, 2011
Egg masses
Q: What do you do when you find yourself in a large, locked room with 29 other guys/girls and an abundant but finite amount of food?
A: Make plenty of babies, of course!
(This makes perfect sense if you are a 4 mm long snail)
I took down my herbivory experiment today and re-weighed all the algae after 4 days of snail grazing. It took about 10 hours in total. But other than grazing on the algae, the Lacuna have been busy making little Lacunas. There were egg masses in all of the snail mesocosms, and most of the algae had at least one egg mass attached. (This made my job a little more difficult because I had to remove the masses before weighing the algae.)
Lacuna eggs on the edge of a sugar kelp (Saccharina latissima) blade
Eggs on the branch of an articulated coralline alga, Corallina officinalis
Also, if you're not a big fan of the algae, you can lay your eggs on your neighbour's back instead. That's what friends with hard shells are for.
:)
A: Make plenty of babies, of course!
(This makes perfect sense if you are a 4 mm long snail)
I took down my herbivory experiment today and re-weighed all the algae after 4 days of snail grazing. It took about 10 hours in total. But other than grazing on the algae, the Lacuna have been busy making little Lacunas. There were egg masses in all of the snail mesocosms, and most of the algae had at least one egg mass attached. (This made my job a little more difficult because I had to remove the masses before weighing the algae.)
Lacuna eggs on the edge of a sugar kelp (Saccharina latissima) blade
Eggs on the branch of an articulated coralline alga, Corallina officinalis
Also, if you're not a big fan of the algae, you can lay your eggs on your neighbour's back instead. That's what friends with hard shells are for.
:)
Sunday, August 21, 2011
Sea lion vs. camera
Digging into the backlog of things I've meant to post, here is an excerpt of one of the videos from the fish diversity recordings featuring a curious sea lion trying to eat the camera...
As it swims off it goes right for the transect tape, which is why you see the tape move up into the camera frame. We've seen this kind of demonic intrusion before...
As it swims off it goes right for the transect tape, which is why you see the tape move up into the camera frame. We've seen this kind of demonic intrusion before...
Summer in Nahant: a first alphabet
This came out of a random conversation with Kylla - the kind of conversation you have when you are both still! in the lab on a Sunday evening - about intertidal Latin name ABCs. I have modified the idea somewhat.
Saturday, August 20, 2011
Things that make my life easier
One of the projects I'm working on in this last month of summer is a repeat of an intertidal experiment we ran last year, with an additional control treatment. In our lab's various studies of rocky intertidal communities, a general method is to conduct regular surveys of the number and abundances of algae and invertebrates like snails.
Two of the most abundant intertidal herbivorous snails. The little snail is Littorina obtusata, the smooth periwinkle (and my favourite intertidal snail!) and the larger snail is Littorina littorea, the common periwinkle.
Survey method: 1. Place PVC quadrat on spot; 2. Record all algae and invertebrates found in quadrat
For field experiments, we set up permanent plot using bolts and washers so we can survey the same plot and track changes over time. However, the markers can be frustratingly hard to find again under all the algae, even if you know where the plot is.
One of my plot markers from last summer. When the tide comes in and out it vanishes under a canopy of algae.
So, the thing that has made my life better: pretty, eye-catching fluorescent zip-ties on the plot market bolts! They significantly reduce search time and make it possible to find and survey 40 plots in a low tide.
Bright yellow zip-tie tag on one corner of a permanent quadrat, labelled washer on the other.
They are so visible among the algae!! You can see more in the background...
Two of the most abundant intertidal herbivorous snails. The little snail is Littorina obtusata, the smooth periwinkle (and my favourite intertidal snail!) and the larger snail is Littorina littorea, the common periwinkle.
Survey method: 1. Place PVC quadrat on spot; 2. Record all algae and invertebrates found in quadrat
For field experiments, we set up permanent plot using bolts and washers so we can survey the same plot and track changes over time. However, the markers can be frustratingly hard to find again under all the algae, even if you know where the plot is.
One of my plot markers from last summer. When the tide comes in and out it vanishes under a canopy of algae.
So, the thing that has made my life better: pretty, eye-catching fluorescent zip-ties on the plot market bolts! They significantly reduce search time and make it possible to find and survey 40 plots in a low tide.
Bright yellow zip-tie tag on one corner of a permanent quadrat, labelled washer on the other.
They are so visible among the algae!! You can see more in the background...
Friday, August 19, 2011
Intrusion intrusion
There is a fishy intruder in my seawater table. I don't know how it got there, but it certainly wasn't there when I set up the experiment yesterday. It most likely got sucked up the pipes for the seawater system, but it looks kind of big for that...
o hai.
o hai.
Fun with herbivory
This blog has been awfully quiet as of late, mostly because I've been insanely busy. I've been back in Nahant for about two weeks now and am working hard to get all the planned research for my algae project done before class starts on the 7th of September and I need to be back in Providence. I've also been helping out with other projects in the lab. But I just got a big experiment up and running, so things will be a little less hectic for a couple of days - mostly simple maintenance and checking up on it.
When I last wrote about the algae project I talked about the big question of "what is it doing here?" We're trying to figure out how the invader is impacting the ecological community. In any introductory ecology class you learn that two of the main interactions between species are consumption (e.g. herbivory, predation) and competition (for space, light, food). My experiment is looking at the first interaction and asking, do the native herbivores in the community eat the invader? How much of it do they eat in comparison to other native algal species? Could this impact growth and survival of the invader relative to other species?
In this case, the herbivore is a tiny little snail, Lacuna vincta, that can occur in relatively high densities on the algae. It is found mostly at shallow subtidal depths, though I have seen it on algae in the low intertidal zone.
Here it is on a ruler. awww.
To see if it has significant preferences for the invader or for the native algae, I put a bunch of Lacuna in a little snail mesocosm (=a food container with holes drilled and mesh glue gunned on) and offer it a choice of the invader, plus five other common algal species. At the same time, I have other snails in other mesocosms that have only one species of alga, so I can compare how much of each species they eat when they have 6 choices vs. no choice over about 3 days.
Multiple-choice mesocosm. There are 6 species in each chamber, and the one on the left has 30 Lacuna snails. The one on the right is a control for any loss/gain of algal mass not due to herbivory.
I have 10 replicates of everything, so 10 x 6 species for single-choice + 10 multiple choice = 70 mesocosms. This means 240 pieces of algae which had to be collected and individually portioned/weighed and 2100 snails which had to be collected and counted. You can see why I've been busy.
Hours and hours of collecting and sorting snails...
Final experimental setup on two seawater tables at the MSC:
When I last wrote about the algae project I talked about the big question of "what is it doing here?" We're trying to figure out how the invader is impacting the ecological community. In any introductory ecology class you learn that two of the main interactions between species are consumption (e.g. herbivory, predation) and competition (for space, light, food). My experiment is looking at the first interaction and asking, do the native herbivores in the community eat the invader? How much of it do they eat in comparison to other native algal species? Could this impact growth and survival of the invader relative to other species?
In this case, the herbivore is a tiny little snail, Lacuna vincta, that can occur in relatively high densities on the algae. It is found mostly at shallow subtidal depths, though I have seen it on algae in the low intertidal zone.
Here it is on a ruler. awww.
To see if it has significant preferences for the invader or for the native algae, I put a bunch of Lacuna in a little snail mesocosm (=a food container with holes drilled and mesh glue gunned on) and offer it a choice of the invader, plus five other common algal species. At the same time, I have other snails in other mesocosms that have only one species of alga, so I can compare how much of each species they eat when they have 6 choices vs. no choice over about 3 days.
Multiple-choice mesocosm. There are 6 species in each chamber, and the one on the left has 30 Lacuna snails. The one on the right is a control for any loss/gain of algal mass not due to herbivory.
I have 10 replicates of everything, so 10 x 6 species for single-choice + 10 multiple choice = 70 mesocosms. This means 240 pieces of algae which had to be collected and individually portioned/weighed and 2100 snails which had to be collected and counted. You can see why I've been busy.
Hours and hours of collecting and sorting snails...
Final experimental setup on two seawater tables at the MSC:
Saturday, August 13, 2011
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