About 100 or so fish in the pond at Madison's Strawberry Patch Park died over the past two days from natural causes.

The pond "turned over" meaning the top and bottom layers of water switched places, because of recent weather, and depleted oxygen levels, said Vern Boothe, Madison's parks director.

After consulting with game biologists, Boothe said the the pond was probably overstocked, which contributed to the problem.

Small bass fry remain alive in the pond.

"The pond is probably healthier now," Boothe said.
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State officials plan to spend $100,000 to pump oxygen into a Buffalo park lake where workers have removed more than 4.5 tons of dead fish.

WGRZ-TV reports that 4.6 tons of dead fish were removed over a three-day period last month from Hoyt Lake in Delaware Park, the centerpiece of the city's parks system designed in the 19th century by famed landscape architect Frederick Law Olmsted.

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The long cold winter wasn't just tough on Minnesotans, it was tough on fish in area lakes.

Minneapolis Park and Recreation Board officials say they're cleaning up fish at several lakes in the city, which died from a lack of oxygen.

Park officials say they're seeing dead fish at Diamond Lake, Grass Lake, Lake Harriet, Lake Hiawatha, Lake of the Isles, Loring Pond and Powderhorn Lake. Both Loring Pond and Powderhorn Lake are seeing more significant fish kills because they are smaller and more shallow.

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Thousands of dead fish have led to a stinky mess in the Detroit suburb of River Rouge.

WJBK-TV reports the gizzard shad recently were found along the shoreline of the community that's located where the Rouge River flows into the Detroit River.

The Michigan Department of Natural Resources says the fish likely died because of the lengthy, cold winter. Other similar fish deaths have been reported in the Lake St. Clair area. The dead fish collect in canals and in near-shore areas. Landowners with large numbers of dead fish should consider burying or composting them.
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An outbreak of dead fish and frogs were recently spotted at the Marquette Park lagoon.

News-Herald correspondent Karen Sala had mentioned this outbreak in her Gage Park column on March 18.

Sala stated that she went to Marquette Park to photograph birds flying.

“I didn’t really see too many birds, so I decided to take a walk instead,” said Sala. “I then noticed no ducks or geese swimming.”

As she approached the water, Sala said she observed hundreds of small dead fish washed up on the shore and even some dead frogs.

“As I walked farther down the path, the bigger the dead fish were getting,” said Sala. “They were on the shore on the path and on the grass across from the path.”

Fish that may be found in the lagoon include, largemouth bass, carps, bluegills and crappies.

“Some of the catfish had to be 24 inches long,” said Sala. “I never imagined there were so many kinds and such big fish in the lagoon.”
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Event/Location	Date	Count	Species	Remarks
Gulf of Mexico (Corpus Christi)	1935	22000000 !22,000,000		Caused by red tide. Also caused coughing, sneezing and watery red eyes in humans.[33]
River Aeron	1974	00010000 !10,000	salmon, trout	Discharge of creamery waste through poorly maintained sewer. Successful prosecution followed.
River Neath	1976	00050000 !50,000	salmon, trout	Extreme drought left fish stranded in stagnant pools into which sewers drained.
River Ogmore	1979	00050000 !50,000	salmon, trout	Spillage of Kymene from a paper mill on the River Llynfi a tributary of the Ogmore. Successful prosecution followed and substantial compensation.
Gulf of Mexico	1986	22000000 !22,000,000	Gulf menhaden, striped mullet, various other species[34]	Caused by red tide.[33]
Rhine River	1986 01	00500000 !500,000		Caused by spill from Swiss chemical warehouse[35]
Texas coast	1997–1998	21000000 !21,000,000		Caused by a bloom of Karenia brevis[36][37]
River Dee (United Kingdom)	2002 07	00100000 !100,000[38]	salmon, trout, roach, perch	Unconfirmed link to release of whey into river
Neuse River, North Carolina	2004 09	01900000 !1,900,000	menhaden	"Natural upwelling" of an acknowledged polluted river. Hydrogen sulfide smell reported[39]
Liuxihe River Guangzhou People's Republic of China	2008 09 09	00010000 !10,000	carp	Unknown[40][41]
Beaches at Thanet, Kent, England	2010 01	00010000 !20,000	velvet crab	20000 + dead crabs - along with dead starfish, lobsters, sponges and anemones. Probably killed by hypothermia.[42][43]
Ting River Fujian People's Republic of China	2010 07	01000000 !>1,000,000 Enough to feed 70,000 people a year[44]		Part of the Zijin mining disaster[45]
Mississippi River; Plaquemines Parish, Louisiana	2010 09	00100000 !100,000[46]	redfish, trout, flounder
Arkansas River; Ozark, Arkansas	2010 12	00100000 !100,000[47]	freshwater drum	Coincided with death of 5,000 red-winged blackbirds that fell from the sky.
Chesapeake Bay	2011 01	02000000 !2,000,000	spot croakers	Included some juvenile croakers. Cold water stress was believed to be the cause.[48]
Jiaxing Xiuzhou District People's Republic of China	2011 01 06	00250000 !250,000	bream, carp, murrel, silver carp, grass carp	Fish caught and transported to market held in large fish tanks fed with river water. Very rapid die-off and loss exceeded 100 tonnes. Only fish caught from a river under China National Highway 320 east died.[49][50]
Redondo Beach, California	2011 03	01000000 !millions	anchovies, mackerel, sardines and other small fish	Caused by oxygen deprivation[51]