01 de enero de 2021

Jan 8th 7-8 pm PST-Lakeside Chat with James Covel: Stories from the Early Days at Lake Merritt

Please register here: https://lakemerrittstoriesearlydays.eventbrite.com
Before there was iNaturalist, before there were smart phones, even before earth-observing satellites, the first municipal naturalist in the United States Paul Covel developed a philosophy and practice of citizen science in Oakland, CA. His motto, "Bringing Nature and People Together" resonates today.
Wishing everyone a safe, healthy and peaceful New Year. We would like to invite you to join us for the first Lakeside Chat of 2021, "Stories from the Early Days at Lake Merritt", featuring James Covel of the Monterey Bay Aquarium (and son of legendary Rotary Nature Center Naturalist Paul Covel).
Friday January 8th from 7 pm-8 pm PST. There will be a 30 minute illustrated talk followed by questions and answers, a trivia game with prizes and discussion. Please share widely with your members and social media.
Description: The story of Lake Merritt is a story of people connecting to nature in the heart of a big city. The city established the first municipal naturalist program in the country (at the first waterfowl refuge in the country) to nurture that connection to nature. We'll dig into this story, and talk about the people that were involved, including Paul Covel, the City's first naturalist.
This is a free, completely online program. A zoom link will be sent to eventbrite registrants before the show.
We are looking forward to brighter days at Lake Merritt and around the world. Take care and hope to seeing you on the 8th.

Anotado en 01 de enero de 2021 a las 04:20 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

21 de diciembre de 2020

Lakeside Chat Recording - Dr. James Carlton - “An Unsolved San Francisco Bay Mystery: The Enigmatic Beach-Hopper of Lake Merritt”

Dr. Carlton's December 4th talk brought us up to date on ongoing scientific research into the origin of the little amphipod found only in the 340 acre tidal lagoon in the heart of urban Oakland, CA. It was fun and a great opportunity to talk with Jim.
If you missed the talk you can view it at https://youtu.be/LHZU24X3OWA.

Answers to questions in Chat can be found here: https://drive.google.com/file/d/1m-dfU4C6WjDyyHgRMGmNUVuonzHImLfT/view?usp=sharing

Lakeside Chats are a monthly series of free online talks about a variety of topics related to Lake Merritt. They are sponsored by Rotary Nature Center Friends (https://sites.google.com/view/stem-at-lake-merritt/home). Please join us for future talks listed on our website.

Anotado en 21 de diciembre de 2020 a las 02:19 AM por ktnoon ktnoon | 0 comentarios | Deja un comentario

04 de diciembre de 2020

Join us tonight for free onine zoom talk by marine biologist, Jim Carlton!

Please join us for our first free online Lakeside Chat program this Fri 7-8 pm by zoom. Marine biologist Jim Carlton is going to talk about an enigmatic little invertebrate that is found only at the lake and was key to his figuring out marine invasions via ballast water. He'll also talk about his pathway to becoming a scientist. We are opening the room with "warm-up" activities at 6:45 pm to bring in and hopefully engage a wide audience including families. (Jim is an Oakland High graduate!)
Please register via eventbrite, tso that you can receive the Zoom link.

Title: An Unsolved Mystery: The Enigmatic Beach-Hopper of Lake Merritt
Fri, Dec 4, 2020 7:00 PM-8:00 PM 30 min talk + Q&A by Zoom
Event URL:https://lakemerritt-mystery_drjimcarlton.eventbrite.com

Best wishes,
Katie Noonan
Rotary Nature Center Friends

Anotado en 04 de diciembre de 2020 a las 01:41 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

11 de noviembre de 2020

Invitation to Jim Carlton's online talk - An Unsolved San Francisco Bay Mystery: The Enigmatic Beach-Hopper of Lake Merritt

Dr. Jim Carlton will kick off a series of talks, "Lakeside Chats", about Lake Merritt, its diverse wildlife and human community. Fri, Dec 4, 2020 7:00 PM - 8:00 pm
Interactive: 25 min of Q&A

Please register at:
Event URL:
https://lakemerritt-mystery_drjimcarlton.eventbrite.com
Lakeside Chats Organizer: Rotary Nature Center Friends

Yes, the scientific name of the iconic Lake Merritt Beach Hopper has been changed from Transorchestia enigmatica to Bulychaeva enigmatica.

Abstact: A small, one-half inch, semi-terrestrial crustacean living in Lake Merritt is one of San Francisco Bay’s biggest mysteries. Beach-hopper amphipods (distantly related to shrimps and crabs) live in a unique but narrow and fragile habitat — the uppermost edges of beaches around the world, and are typically found under decaying seaweed, driftwood, and rocks. Our native beach-hoppers are found both in San Francisco Bay and along outer coast beaches. However, one species of beach-hopper, Bulychaeva enigmatica, is found in only one place in the world — Lake Merritt! Is it a native relict of the Bay Past, or a non-native species from somewhere else in the world? We trace its discovery, the most current thinking about its origins, and how this enigmatic beach hopper may have come to be in Lake Merritt.

See you there! Katie Noonan

Anotado en 11 de noviembre de 2020 a las 04:13 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

17 de octubre de 2020

150th Anniversary of the Lake Merritt Wildlife Refuge

It's the 150th anniversary of the first wildlife refuge in the nation - Lake Merritt in Oakland!
There will be a virtual celebration on Friday, October 23rd 7-8 pm on the Zoom.

Hear live-streamed remarks from marine biologists Jim Carlton and Andrew Cohen,and many other speakers from science, history, conservation and environmental justice. Time permitting, there will be an opportunity to ask questions via chat.

See the full list of speakers on the Eventbrite invitation. Zoom link will be sent via email before the program.

Please register online for a thoughtful, upbeat, fun community education event. FREE.
https://lake-merritt-wildlife-refuge-150th.eventbrite.com

Anotado en 17 de octubre de 2020 a las 11:33 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

06 de mayo de 2020

City Nature Challenge - Lake Merritt BioBlitz 2020

The City Nature Challenge was a great occasion to resurvey the aquatic life at the Lake Merritt Boating Center dock. Thank you to the California Academy of Sciences Citizen Science Department and to the observers and identifiers who contributed to the Lake Merritt BioBlitz 2020. Thirty aquatic species were observed at Lake Merritt this year, in comparison to seventeen last year.

Here is a species list and some observations about differences between this year and last.

Physical conditions: Observed on Fri 4/24, 2020 at Lake Merritt Boating Center Docks
Cool and windy, water temperature 20 degC , salinity 30 ppt; dissolved oxygen 8 ppm, pH 7.5, Secchi 170 cm. Tide gate was probably closed, low tide levels. Lake Merritt received only 1.67 inches of rainfall Jan-Apr 2020, compared to 13 inches in Jan-Apr 2019. Last year, water temperature was 23 degC and salinity was only 22 ppt, .

2020 LAKE MERRITT BIOBLITZ SPECIES LIST
Sponges
Halichondria bowerbanki - Deadman’s finger sponge
Clathria prolifera (by tide-gate) Red-Beard sponge

Sea Anemones
Diadumene lineata - Green-striped anemone
Diadumene franciscana San Francisco anemone

Mollusks
Bivalves
Teredo navalis – Ship’s worm (observed 4/22/2020) or possibly Bankia
Mytilis galloprovinciali*s Mediterranean mussel - Photos taken, smooth not ribbed, all sizes
Mya arenaria – Soft-shelled clam
Ruditapes philippinarum - Japanese Littleneck clam (shell only)

Gastropods
Haloa japonica– Japanese Bubbleshell, many egg masses
Urosalpinx cinerea- Eastern Oyster Drill - several adults and egg cases
Tritia obsoleta- Atlantic Mud Snail

Crustaceans
Palaemon macrodactylus – Oriental shrimp (observed 4/20/20)
Corophiums
Other amphipods
Gnorimosphaeroma oregonense, Sphaeroma quoiannum, needs i.d. - Oregon pillbug
Amphibalanus improvisus – Bay barnacle - many small barnacles encrusting mussels on dock

Worms:

Polychaetes:
Australian tubeworm - Ficopomatus enigmaticus
Pile worm - Nereidae
Fifteen-scaled worm- Harmothoe imbricata
Unidentified polychaete and polychaete larvae.
Syllidae (in plankton)

Nematoda (in plankton)

Tunicates:
Ciona savignyi – Solitary sea squirt
Botryllus schlosseri - Star tunicate
Botrylloides diagenesis - San Diego tunicate
Styela clava – Club tunicate
Acidia zara (?)
But no Molgula manhattensis - unless the misshapen ones with heavy skin flagging are aging M.m.

Plankton:
Coscinodiscus
Pennate Diatoms- Several kinds
Chain diatoms
Tintinnids
Polychaete larvae
Copepods in various stages mostly immatures
Gastropod larvae
D-shaped bivalve larvae.

Sea Weeds: Cladophora (this is possibly incorrect), red algae that needs to be identified (uploaded to iNat as Sarcodithia or Gracillaria). Observed (4/20-4/22) - Enteromorpha, Ulva sheets, Codium fragile floating.

Fish
Gobies, Northern Anchovies, mosquito fish, topsmelt silversides, Northern Pipefish

Not observed last year in BioBlitz: Red Beard Sponge, Styela clava, Diadumene franciscana, Star tunicate, San Diego tunicate, Bay barnacle, Japanese Littleneck clam,

Not observed this year: Okenia plana, rainwater killifish, red-striped barnacle, Asian date mussel, Conopeum, other bryozoans

https://www.inaturalist.org/projects/lake-merritt-2020-city-nature-challenge
https://www.inaturalist.org/projects/lake-merritt-bioblitz-april-2019-city-nature-challenge

Anotado en 06 de mayo de 2020 a las 04:30 AM por ktnoon ktnoon | 0 comentarios | Deja un comentario

12 de enero de 2020

Critter Hunt at Lake Merritt with Naturalist Damon Tighe

Great turnout for citizen science activities at Lake Merritt! We've got something going here. Thanks to everyone who identified organisms, collected plankton and helped drive the underwater robotic vehicle, and especially to Damon who shared his natural history and photography expertise.

Here is a preliminary species list for the day. We saw and mostly photographed at least 23 species not including plankton. There were a lot of phytoplankton, mostly Chaetoceros and many zooplankton of the usual types (copepods in different stages, evadne, mollusk larvae, polychaete veligers). Rate-Our-Plankton level = Tiny Threads

CRITTER WALK Water quality:
Water Temperature 12top/
Salinity 30 ppt top/30 ppt bot
pH 7.5 top/7.5 bot
D.O. 9 ppm/7 ppm
Secchi 100 cm, Depth 150 cm

CRITTER WALK SPECIES LIST:
Red-eyed Medusa - Jelly- Polyorchis penicillatus
Sponge Halichondria bowerbankia
Sea anemones

Diadumene spp. double white striped, orange striped
Diadumene franciscana

Crustaceans
Red-striped barnacle Amphibalanus amphitrite
Amphipods
Roly-Poly Isopod Sphaeroma quoianum
Oriental shrimp Palaemon macrodactylus

Mollusks
Bay mussel Mytilis galloprovincialis
Soft-shell clam Mya arenaria
Philippine littleneck clam Ruditapes philippinarum (shell only)
Mud snail Tritia obsoleta
Bubble snail Haminoea japonica
Oyster drill Urosalpinx cinerea

Sea squirts
Ciona savignyi
Molgula manhattensis
Botryllus schlosseri
Botrylloides violaceus

Worms:
Tubeworm Ficopomatus enigmaticus
Scale worm Harmothoe imbricata
Spaghetti worm Terebellid
Spionid Boccardia proboscidea

Bryozoans:
Branching bryozoan Bugula
White crust Conopeum sp.

Red algae Lomentaria hakodatensis (?) mentioned in Chang et. al poster about Lake Merrittt,
“A Classic Estuarine Lagood of the 1960’s Undergoes Oceanization by the 2010’s: Remarkable Changes in the Biodiversity and Community Composition.” 2017 State of the San Francisco Bay Estuary Conference Abstracts p. 118

Zooplankton:

Phytoplankton:

To be revised and continued.

Anotado en 12 de enero de 2020 a las 07:32 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

01 de diciembre de 2019

Plankton tow on November 29th, 2019

Anticipating the upcoming week of rainfall, I thought I'd check out the plankton in Lake Merritt before the brackish water goes fresh. The surface water went from a well-mixed salinity 32 parts per thousand (ppt) on Nov. 24th to stratified 22 ppt at the top and 31 ppt at the bottom on November 29th after a brief rain when I took my plankton tow. I photographed plankton with my iPhone through a student microscope at 40 and 100 x magnification. The photos are in the Lake Merritt Species Project. It will be interesting to see what changes happen after the storms.

Taken from west side of longer open floating dock.
Water depth 210 cm, temperature 9 degrees Celsius top/12.5 degrees Celsius bottom, dissolved oxygen 4 ppm/3.5 ppm bottom, salinity 22 ppt top/31 ppt bottom, pH 6.5 top/7 bottom, Secchi 110 cm.

Plankton net used was 50um mesh.
Magnification was either 40X or 100X. Photos by student microscope and iPhone.
Rate-Our-Plankton-Density = CLEAR

PHYTOPLANKTON: https://www.eoas.ubc.ca/research/phytoplankton/index.html
Thalassiosira (although I think I see two central connecting strands not one)
Melosira, several stages of copepod (nauplius and calanoid?).
Chaetoceros - corkscrew -type (according to hand-out from Romberg Tiburon Center event this is a different species from the straight Chaetoceros), Chaetoceros debilis
Asterionellopsis
Achanthes
Coscinodiscus,
Nitzchia
Navicula,
Something – Skeletonema?
https://www.eoas.ubc.ca/research/phytoplankton/diatoms/centric/skeletonema/s_costatum.html

ZOOPLANKTON
Copepods: copulating copepods with long antennae, 2 kinds of copepods,
Polychaete larvae with big heads with bristles and skimpy bodies, many zooming trochophore larvae
Flatworm-type worm
Possible barnacle larvae distinguished from copepod nauplii by jerky swimming style (helpful hint from Charles Ford),

When viewed plankton sample was 2 hours -2 days old ☹.

Anotado en 01 de diciembre de 2019 a las 04:42 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

03 de noviembre de 2019

Thanks to Amy Bohorquez' Biology class at Laney College for field work on October 24th!

10-24-species list: Sampled from 2 places: Lake Merritt Boating Center dock (Carlton site G) and the amphitheater beach area (Carlton site C). I brought organisms from dock to the class meeting place by amphitheater green pedestrian bridge.

Water quality measurements were taken from the green bridge over the entrance to Lake Merritt Channel: Temperature 20 degC top/22 degC bottom; Salinity 27 ppt top/bottom; Secchi depth >1.25 m; Dissolved oxygen 7 ppm top/8 ppm bottom; pH 7 top/7 bottom; 2:30 p.m.; ebb tide.

Amphibalanus amphitrite C,G
Amphibalanus improvisus C (not sure of that)
Mytilus galloprovincialis C,G
Breadcrumb sponge (Halichondia bowerbanki) G
Diadumene sp. (large, long tentacles, barrel covered by debris). G
Ciona savignyi G
Molgula manhattensis G – hardly any compared to 9-14
Bottrylus schlosseri G
Ficopomatus enigmaticus G
Worm that build big mud tubes.
Tan arborescent bryozoans G
Mya arenaria G
Ruditapes philippinarum shell only C
Haminoea japonica G
Urosalpinx cinerea G
Caprellid - Skeleton shrimp G
Sphaeroma quoianum C, G
Amphipods
Sea lettuce Ulva
Cladophora (?)
Red algae

Anotado en 03 de noviembre de 2019 a las 04:19 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario

13 de octubre de 2019

Final Species List and Discussion for Andrew Cohen's September 14th and October 5th "Critter Walk."

Again many thanks to Dr. Cohen!

Critter list for Lake Merritt walks on 9/14/2019 and 10/5/2019
Duck Ponds to Boathouse Docks

  • indicates that the species is in www.exoticsguide.org.
    (N) indicates a native species and (I) an introduced non-native species.

Sponges (Porifera)
Halichondra bowerbanki (yellow sponge, crust-of-bread sponge) (I) on dock sides (9/14 & 10/5)

Anemones (Anthozoa)
Diadumene lineata* (I) on rocks & dock sides (originally named Sagartia luciae); green column, sometimes with vertical orange lines on column, yellowish tentacles (9/14 & 10/5)
Diadumene leucolena (I) with vertical double white lines on column; on dock sides & rope (9/14)
(The anemone I said was a Metridium on 9/14 might have been D. leucolena.)

Sea worms (Polychaeta)
Ficopomatus enigmatica* (I) (tube worms on dock sides and on rocks below upper zone of barnacles) (9/14 & 10/5)
Terebellid worm (Spaghetti worm) in clay tube, collected at docks (10/5)

Snails & Sea Slugs (Gastropoda)
Tritia obsoleta* Atlantic Mudsnail (I) on mud and rocks (9/14 & 10/5; egg cases on 9/14 only)ly)
Urosalpinx cinerea* Atlantic Oyster Drill (I) snails with yellow or orange, ocassionally white, shells, on rocks and dock sides (9/14 & 10/5; vase-shaped egg cases found under rocks on 10/5)
Assiminea californica (N) tiny brown snail on underside of rocks (9/14) (there are pictures of Assiminea on the Myosotella myosotis page at www.exoticsgide.org)
Haminoea japonica (I) slugs, kidney-shaped gelatinous egg masses with yellow eggs, and a few delicate, transparent internal shells found on rocks, dock sides, undersides of rocks (9/14 & 10/5; egg masses abundant and slugs fairly common on seaweed on 10/5)

Clams & Mussels (Bivalvia)
Geukensia demissa* Atlantic Ribbed Horsemussel (I) shells on mud, live mussels on rocks and undersides of rocks (9/14 & 10/5)
Mytilus trossulus (N), Mytilus galloprovincialis (I), or hybrids Bay Mussel or Blue Mussel - on rocks, dock sides, ropes, undersides of rocks (9/14 & 10/5)
Arcuatula senhousia* Green Bagmussel or Asian Date Mussel (I) on rocks, dock sides, underside of rocks (9/14; empty shells and parts of shells found among Mytilus byssal threads on 10/5)
Mya arenaria* Eastern Softshell Clam (I) shells common on mud (9/14 & 10/5; small live clams found among Mytilus byssal threads on 10/5). (Cryptomya californica, a native species in the same family that also has a chondrophore—a shelf-like structure that forms the hinge on the left valve—discussed in connection with its shallow pallial sinus and association with burrows of other animals).
Ruditapes philippinarum* Japanese Littleneck Clam, Manila Clam (I) someone brought me one empty shell near the end of the walk on 9/14
Leptostraca
Probably in the genus Nebalia or an allied genus - Katie Noonan found one near the docks. (9/14)

Barnacles (Cirripedia)
Amphibalanus amphitrite* (I) on rocks (9/14 & 10/5)

Rolly-pollies, sowbugs (Isopoda)
Sphaeroma quoianum (I) the larger isopod, among barnacles and in empty barnacle shells on the sides of large rocks (on 10/5) and on undersides of smaller rocks (9/14 & 10/5); usually with a double row of 4 bumps on its tail segment; this spices sticks out the small limbs alongside its tail segment ("uropods") when it rolls up into a ball
Gnorimosphaeroma oregonense (N) the smaller isopod, on the undersides of rocks; often with a broad, gray stripe along its back; does not stick out the small limbs alongside its tail segment when it rolls up into a ball (9/14 & 10/5)
(Discussed: Iais californica (I) commensal on the underside of Sphaeroma quoianum)

Scuds, Sand Fleas (Amphipoda)
Unidentified amphipod in the suborder Gammaridea - underside of a rock (9/14)
Skeleton shrimp - on dock sides; these are highly modified amphipods in the family Caprellidae (9/14 & 10/5)

Crabs & Shrimp (Decapoda)
Pagarus sp. Hermit Crab (N) in an Oyster Drill shell, on rocks (9/14)
Palaemon macrodactylus (I) one found among dock fouling; Asian shrimp thought to be from Korea based on its discovery in the Bay around the time of the Korean War (10/5)

Bryozoa
Conopeum tenuissum? - small colonies of an encrusting, membraniporine bryozoan that may be this species, on organisms attached to dock sides (9/14 & 10/5)
unidentified arborescent (branching, bushy) cheilostome bryozoan - small colonies on dock sides (9/14 & 10/5)

Sea Squirts (Tunicata)
Molgula manhattensis (I) very abundant on the dock sides (9/14 & 10/5)
Ciona savignyi (I) I saw one that was dound on the side of the docks (10/5)

Fish
Tridentiger sp. Goby (I) on mud (10/5)

Marsh Plants (I've listed the typical zonation pattern, but this may be less apparent in the small bits of recently-created brackish marsh at Lake Merritt)
Baccharis pilularis Coyote Bush (N) - high marsh/dry land transition (9/14 & 10/5)
Grindelia stricta Gumplant (N) - high marsh and slough levees (9/14 & 10/5)
Distichlis spicata Salt Grass (N) - high marsh (9/14 & 10/5)
Limonium Marsh Rosemary or Sea Lavendar (N) - high marsh (9/14)
Salsola soda Mediterranean Saltwort (I) - high marsh (9/14 & 10/5)
Jaumea carnosa (N) - marsh plain (9/14 & 10/5)
Sarcocornia pacifica (formerly Salicornia virginica) Pickleweed (N) - marsh plain (9/14 & 10/5)
Frankenia salina Alkali Heath (N) - marsh plain (9/14 & 10/5)

Birds of Note
Canada Geese and Mallard Ducks (9/14 & 10/5) On 10/5 discussed the biological, morphological, genetic and ecological species concepts; on 9/14 & 10/5 discussed Dave Wilcove's concept of Canadoids and Mallardoids, and Dave Covel's introduction of Canada Geese to Lake Merritt.
Double-crested Cormorants (9/14 & 10/5) On 9/14 we had the lovely experience of watching a comorant swim around underwater in front of us searching for a snack as gobies scattered before him; and discussed observations in the 1940's of regular "team fishing" by enormous flocks of comorants in San Francisco Bay between Berkeley and Emeryville.
Great Egret (9/14 & 10/5)
White Pelicans (9/14)
Coot (10/5)

Some Other Discussions
California Ridgway's Rail (former name: California Clapper Rail, which I still tend to use) interactions with the Atlantic Ribbed Horsemussel. (9/14 & 10/5)
The interactions of Saltmarsh Song Sparrows and Marsh Wrens in non-native cordgrass marsh. (9/14)
Clam shell anatomy; the size of the pallial sinus as an indicator of a clam's ecology (depth in the mud and types of predators); and why the native clam Cryptomya californica is typically found at depth despite its small pallial sinus. (9/14 & 10/5)
The recent and ongoing extirpation of the native mudshrimp by a non-native bobyrid isopod parasite; and how the arrival of a non-native mudshrimp may eliminate any density-dependent restriction of the parasite's impact on the native mudshrimp population. (10/5)
My hypothesis that marine avian schistosome populations are sustainable only at sites where both the snail host and the primary avian host are present in great abundance, and may be spread to temporary, secondary sites by the bird hosts. In the case of San Francisco Bay's two swimmer's itch outbreaks at Crown Beach in Alameda, the main populations may have been at the Lake Merritt bird sanctuary, where both water birds and snail hosts are abundant, and exported by commuting birds to create a secondary population at the beach where people regularly wade in the water and are exposed to the cercaria. (10/5)

Anotado en 13 de octubre de 2019 a las 07:57 PM por ktnoon ktnoon | 0 comentarios | Deja un comentario