Weekend #Plankton#Factoid 🦐🦠
There is a well-known ecological relationship called Bergmann's Rule which states that populations & species of larger size tend to be found in colder environments at higher latitudes. This pattern also holds true for #phytoplankton and #zooplankton. Polar #copepods like Calanus hyperboreus (~5 mm) are relative giants compared to tiny tropical Parvocalanus crassirostris or Oithona spp. (300-400 µm). These tiny copepods were regularly missed by coarse mesh nets.
Weekend #Plankton#Factoid 🦐🦠
A new paper on #mixotrophs. These protists are both plants or animals. Some algae, often #dinoflagellates, can consume other organisms in addition to being able to photosynthesize. They switch as needed, and during the recent heat-waves driven by #ClimateChange, they become dominant. The fate of this production isn't well known because some species are often not preferred for grazing #zooplankton because of toxicity or armoured cell walls.
Weekend #Plankton#Factoid 🦐🦠
The ubiquitous tool of #zooplankton#science is the Plankton Net. The first documented use was by British surgeon Dr John Vaughan Thompson to catch the brightly coloured copepods Sapphirina and barnacle larvae. Darwin brought these nets on the HMS Beagle. Originally fine muslin, then silk, now are highly accurate sized meshes of nylon. Modern quantitative #oceanography nets with removable cod-end have been standardized since late 1800s and named for Victor Hensen.
Weekend #Plankton#Factoid 🦐🦠
For #zooplankton, there are few true rules about feeding. Herbivores will consume prey, and omnivores will consume anything they can handle - live or dead. #Jellyfish are often viewed as poor food, rarely consumed, so "jellyfication" of the oceans was thought a concern. While #metabarcoding has its issues, it makes possible identification of trace prey, and #Arctic amphipods are confirmed to eat gelatinous zooplankton esp if food is scarce. https://phys.org/news/2024-02-tiny-crustaceans-preying-jellyfish-harsh.amp
#Copepods are one of the most numerous metazoans on the planet. They are also capable of insanely fast #swimming escape speeds (20 cm/s) and super sensitive to their environment through mechano- and chemosensors on their antennae. Something not as well known is that their nerves are coated in myelin (often thought found only in vertebrates). This gives them 3x faster reponses to predators. Very sophisticated for a 1-2 mm long #zooplankton. https://www.researchgate.net/publication/12518174_The_need_for_speed_II_Myelin_in_calanoid_copepods
Der Klimawandel bedroht neuen Untersuchungen zufolge das gesamte Ökosystem in der Arktis. Forscher warnen vor Folgen für alle Meeresbewohner - vom Zooplankton bis hin zu Robben und Eisbären. Von J. Meier-Wendtke.
WE HAVE UNTIL AUGUST 11 TO STOP MASSIVE SEISMIC BLASTING
The #SeismicBlasting proposal between Victoria and Tasmania impact #BlueWhale habitat and the #ZeehanMarinePark .
A joint venture between seismic survey companies #TGS and #SLB-Schlumberger is trying to get regulatory approval for seismic blasting over 55,000 sq km of our #oceans. Now is our chance to provide public comment that these plans should be refused to protect our oceans and #MarineLife.
Seismic blasting is deadly for marine life and can impact all levels of the food chain from its very foundations, killing #zooplankton more than a kilometre away, to deafening #whales.