A jellyfish swarm, also known as a bloom, smack or mass aggregation, occurred in Port Angeles Harbor on Friday, November 15, 2024. Several jellyfish species, and similar jelly-like but not jellyfish species called salps, were sighted pouring into the harbor alongside the inner tip of Ediz Hook. Jellyfish are also known as sea jellies. The number of jellies in this smack is unknown, but likely ranged from hundreds of thousands to over a million.
Jellies and salps are both simple and amazing creatures. They appear in large groups and as solitary animals. Jellies only have one body hole (for mouth, anus, and reproduction). Jellies swim and salps have jet propulsion. They navigate. They hunt. Jellies have spring loaded and poison tipped barbed darts. They eat anything that will fit in their hole. They have a unique life cycle and reproduce through multiple methods. They are sensitive to climate change and they have replaced whole fisheries in some parts of the world.
Jelly swarms (blooms, smacks or aggregations)
Jellyfish swarms are increasingly common in the Puget Sound, and have recently been the subject of study by the Washington State Department of Ecology (DOE) in 2014-2015. It’s hard to count the total number so aggregations are measured by “mass category,” which ranges from a mass size of 1 to 5, where 5 is the largest. Mass size tends to be larger in late summer-fall. In November, mass sizes counted have ranged from about 2.2-3.8. A jellyfish smack can “easily exceed hundreds of millions of individual” animals in an individual Puget Sound finger inlet, such as Budd Inlet.
Jelly and other species observed in the PA smack
Several observers predominately saw cross jellies, both younger and older adults and juveniles. Also seen were crystal jellies, moon jellies, egg yolk jellies, box jellies, water jellies, and beautiful and stinging pacific sea nettles. Salps and sea lice were also seen.
Some jellies were hard to identify. Do you know what they are?
Salps, and this other string critter were seen in abundance. Salps are not jellyfish and not even related. They have a spinal chord, which makes them related to humans and all vertebrates. Salps use jet propulsion to move themselves in any direction. I don’t know what the string critter is, but it definitely also had propulsion and was able to move against the current in the marina. An observer from New Zealand said they called them sea lice and that they sting as they wrap around you.
There were quite a number of deceased jellies washed up on shore after the morning high tide on Saturday, November 15, 2024, such as the moon jelly below with the C-shaped purple sex organs. The crystal jelly’s ridges under the outer bell are rigid like a washboard.
The next day, Saturday, November 16, 2024, a few jellies were seen in all parts of the harbor. They were also seen inside the Port Angeles Boat Haven (marina), but not in mass quantities. One small exception was the collection of crystal jellies in the pictures below. Interestingly, these were hovering at the tail of a freshwater outlet pipe. The water flow from the pipe was substantial, and clear, and the jellies were fighting successfully to stay close to the pipe outlet. But why?
What is a jellyfish?
They are surprisingly interesting animals, both extremely simple and complex. The have no blood, no heart, no lungs, and of course no bones. They have no brain, although they have a nervous system which senses and responds to the environment.
Jellyfish eye
Some species have a more evolved nervous system and a rudimentary eye. In some species the “eye” is very simple and only senses for light. In other species, particularly the box jellies, they have a more evolved structure clearly identifiable as an eye, or even a set of multiple eyes, which they use to move toward or away from light and also to navigate around obstacles.
One body hole
A jelly has one hole: the mouth is also it’s anus and entry/exit way for the sexual organ. Yes, it eats and poops and delivers and receives sperm and eggs from the same hole.
Some jellyfish facts
There over 2,000 jelly species. The bell height and diameter ranges by species from 0.5 millimeters (1/32 inch) to 2 meters (6.5 feet, not including the mouth parts which can extend out further). Their tentacles can range from 1 inch long to 119 feet long. The lion’s mane jelly is the longest, longer than any whale, and may be the longest animal on the planet. Lion’s mane jellies live in the Salish Sea, although they are not reported as growing that large here.
They can release as many as 45,000 eggs daily.
Their diet is varied and includes plants and animals tiny to small: protozoa, phytoplankton (plant), plankton (animal), zooplankton, rotifers, eggs, crustacean larvae, larval fish, small fish, crustaceans, and other jellies. Each species eats different things, but most or all are carnivorous. Some eat whatever attaches to their tentacles and fits in their mouth, so any kind of small creature.
Jellies swim, and navigate
Jellyfish are not simply passive creatures subject to the whims of currents, like plankton. Typically they move about 5 feet per minute, and some can travel up to 4 meters (12 feet) per minute. They can move in any direction including against the current. Some species, like the pacific sea nettle can move up and down the ocean’s water column 3,600 feet per day. Yes, per day!
I watched this pacific sea nettle in the gallery below swim around in the Port Angeles Boat Haven. I first saw it swim (west) past the wood pier, which was up-current. It then turned 90 degrees and swam to the left (south), bumped into a wooden bulkhead, turned around 180 degrees and swam north past that pier post, and then again west, where it bumped into a cement pier. Despite the current wanting to push it east, it stayed in that area for about 15 minutes.
Two types of tentacles
The long stringy tentacles are the true tentacles and contain all or almost all the stingers. The other kind are called oral arms, which assist with collecting food and bringing it to the mouth inside the bottom of the bell. The oral arms can also hold a brood of baby jellies (called polyps). For the pacific sea nettle jelly (above), the red strings growing out sides of the bell are the tentacles and the lighter colored mass that flow from the middle of the bell are the oral arms.
Some jellies, like the moon and crystal jellies, have small or no apparent oral arms.
Sometimes the tentacles are translucent or fine like a hair, and difficult or impossible to see.
Jellies hunt with poison tipped and spring loaded barbed hooks
Jellies can sense their prey and move towards it. They hunt!
Jellyfish are voracious hunters. Their vortex-creating swimming action also draws in food to the tentacles and they never stop swimming or eating.
Jelly tentacles have an amazing weapon. Each tentacle is loaded with many, sometimes millions of spring loaded barbed hooks filled with a neurotoxin. The lion’s mane jelly can have 1,200 tentacles, some up to 119 feet long, covered in cysts containing the barbed hooks.
Jellies don’t always have the intelligence to know if something they touch is prey or not, which is why they attack people. The release of the barbs is automatic. Lion’s mane, pacific sea nettle and box jellies sting people. The Portuguese man o’ war is renowned for it’s painful sting (although it’s not technically a jellyfish), but the Australian box jelly (chironex fleckeri) is the most deadly jelly. It can kill a human in a matter of minutes if medical help isn’t received. It’s poison was analyzed to include an amazing cocktail of 170 toxin proteins.
Some fish are immune to the poison of some jellyfish, and they’ll swim around and within the tentacles and oral arms for protection. (Some fish do the same with corals, which are in the same family tree as jellies.)
Most jellies in the Salish Sea have very mild poison in their barbs. Sea anemones are also in the same family. They too inject little barbs, which is why they feel like Velcro when you stick your finger in them. But, their poison has no noticeable effect on humans. When these creatures don’t need to eat larger prey, they don’t need strong poison.
Jelly fish are hunted, a little bit
It can be hard for scientists to determine which animals eat jellies because even if they look in their stomachs it’s hard to identify jellies from all the other goo in the a stomach. A few animals are known to eat jellyfish, including sunfish, sea turtles, sea cucumbers, crabs, shrimp, seagulls, penguins, sea lions and seals.
Jellies are 96% water so they are not a calorie dense food. However, the inner parts like the stomach pouch, sexual organs and tentacles are nutrient rich so predators often target these parts. Unless immune to the poisonous barbs, an effective strategy is to eat the innards from the top, through the bell material. In the Port Angeles Harbor swarm I saw a number of dead jellies with parts or the middle of their bell missing.
Some websites claim that salmon will eat jellyfish. However, in one incident in Ireland a smack of poisonous jellies were swept into salmon farming pens and quickly killed all the salmon. (See the David Suzuki video referenced below for video footage.)
Unique life cycle
Jessica Schaub, a masters student at University of British Columbia, researches jellyfish, and the moon jelly in particular.
She describes how Jellies start as a planula larva, a tiny critter .2 millimeters in size, with 8 tentacles. They are so small their growth and eating behavior can only be studied under a microscope. They grow into polyps which are raised on the underside of the bell or within the oral arms. Eventually they release from their mother and swim around until they find something to attach to, which is usually a rock and can be the underwater portion of a dock structure. The larva grows into a small polyp which lives for many years in a colony.
When the polyps get old enough, they start shedding new jellies, about 10 per year for moon jellies. That process is sort of like growing a flower which eventually wiggles off the main stem. The polyp is cloning itself.
The little clone is a baby jelly, about the size of a quarter (2.5 centimeters, or 1 inch in diameter) called an ephyra. The ephyra grows into a full size jellyfish in about 2 months, super fast. The adult is scientifically called a medusa, because of the bell-shaped body with tentacles.
The polyp can be considered the main animal. The medusa’s purpose is to mate and produce more larva. The medusa usually dies shortly after producing babies, but the polyp lives on for years, creating new clones.
Jessica describes in her video the amazing process of how the polyp can also clone a new polyp or a podocyst which is a seed like critter that can float away and attach to a surface to grow into a new polyp. Podocysts can hibernate if growing conditions are not favorable.
Polyps can attach to rocks, but also plastic, wood, common dock building materials. Human activity thus creates more living environments for jellyfish communities.
So if I understand this right, a polyp reproduces three ways. It can make little podocyst’s, it can make a new polyp, and when it sheds an ephyra it’s basically making a clone of itself whose primary job is to eat, grow, and sexually reproduce new babies from sperm and eggs. Wow.
Jessica’s YouTube video on her research is at https://www.youtube.com/watch?v=vAvTd4Lf1Ik.
Jellyfish and climate change
Jelly smacks are common in the summer, and may be increasing in Puget sound. They are increasing in some parts of the world, sometimes with severe economic and environmental impact.
The Nature of Things documentary on jellyfish by David Suzuki provides a nice overview of their complex nature and harm to world fisheries.
Jellyfish appear to be capable of quickly and massively colonizing regions that are damaged from overfishing or suffering other detrimental environments for fish. Fish and jellies compete for resources. In places where jellies have taken over it is hard for fisheries to re-establish themselves.
Preventing jellyfish from overtaking an ecosystem has proven hard to accomplish.
World Jellyfish Day
The November 15 2024 Port Angeles smack missed the November 3rd World Jellyfish Day celebration in Port Angeles by 12 days.
I hope you enjoyed this story of another amazing and elusive creature on the Olympic Peninsula and it’s waters. If you have some pictures of the Port Angeles smack and want to share them in this article, contact us at the link above.
This article is part of a series on nature in the Olympic Peninsula. Please consider contributing to the series.
I spoke to one local sport fisherman who said he caught an unusual amount of jellyfish in his lines last year. If you have any similar experience, with an increase or not noticing any at all, please let us know.
Mark Baumann