''Pacifastacus fortis'' (known as the Shasta crayfish or placid crayfish) is an
endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...
crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
species
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to
Shasta County
Shasta County (), officially the County of Shasta, is a county in the northern portion of the U.S. state of California. Its population is 182,155 as of the 2020 census, up from 177,223 from the 2010 census. The county seat is Redding.
Shasta ...
,
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, where it is found only in isolated spots on the
Pit River
The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range.
The longest tributary of the Sacr ...
and
Fall River Mills
Fall River Mills, colloquially referred to as Fall River, is an unincorporated town and census-designated place (CDP) in Shasta County, California, Shasta County, California, United States. Its population is 616 as of the 2020 census, up from 573 ...
. The exact subpopulations for the Shasta Crayfish were discovered in 2004 through a genetic study that determined three different
genetic clusters: Crystal Lake, the Big Lake group (which include Big Lake Springs, JeShe, Lava, and Spring Creeks), and Thousand Springs.
Description and ecology
''P. fortis'' is thick and stocky, with relatively heavy
chelae
A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...
. It is usually dark brown dorsally with bright orange areas on its underside. These colors aid in camouflage in its habitat. It grows about 2-4 inches long. It lives in cold, clear, rocky areas of the mountain rivers, and feeds on microbes, algae, and small animals like snails.
The animal requires a constant, steady, and untainted flow of fresh water to survive. ''P. fortis'' have 5 pairs of legs.
With regards to life span, ''P. fortis'' tends to endure a life span of between 10-15 years on average.
Reproduction occurs once per year, typically in October, when older females produce up to 40 eggs per year and younger females produce fewer eggs. By May, most eggs will have hatched and the babies stay attached to their mother for a short duration before separating and becoming a free-willed organism ''P. fortis'' is nocturnal and remain idle behind cover for the majority of the day. They begin to leave their cover only when it is night and light is scarce. Furthermore, when possible, it prefers to live on its own without other members from its species.
Predators in California include but are not limited to various species of fish, such as the
Ameiurus nebulosus
The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''A ...
,
Cyprinus carpio
The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...
, and
Salmo trutta
The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...
. Competitors include the
Pacifastacus leniusculus and the
Micropterus dolomieu.
Causes of endangerment
''Pacifastacus fortis'' is listed as a
critically endangered species on the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
,
and an
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
under the
Endangered Species Act
The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...
.
Numerous factors play a role in the endangerment of ''P. fortis.'' Within California, some minor factors include but are not limited to illness and invasive predators. However, human intervention affects the species at a much greater proportion. Urbanization, pollution, and other forms of intervention often affect the surroundings of ''P. fortis,'' ultimately resulting in significant habitat loss and consequently, a significant decrease in population.
It has always had a very small native range, and that range has been significantly fragmented by such human activities as damming, mining, and agriculture. The
Pit River Fish Hatchery was closed to protect this species.
Two
introduced crayfish species, ''
Pacifastacus leniusculus'' and ''
Orconectes virilis'', as well as
water impoundment and diversion have contributed to the continuing decline of ''P. fortis''. Chemicals from agriculture have also washed into streams, and groundwater has been pumped to the point of lowering the water table, further decreasing the numbers of ''P. fortis''.
Hydroelectric operations in the area have also contributed to habitat loss, destroying almost all of the preferred substrate of ''Pacifastacus fortis''.
Its decline mimics that of its closest relative, the ''
Pacifastacus nigrescens'' crayfish, who’s similar habitat loss and aggression from invasive species led to its eventual extinction. Attempts at controlling or extirpating invasive species are very expensive and rarely succeed;
reintroducing
Species reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse, self-sustainin ...
''Pacifastacus fortis'' to California cost $4.5 million.
''P. fortis'' is the only native crayfish remaining in California.
Conservation efforts
The Shasta Crayfish was designated as a
rare species by California law in 1980 and an
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
in 1988 by the
Federal Government
A federation (also known as a federal state) is a political entity characterized by a union of partially self-governing provinces, states, or other regions under a central federal government (federalism). In a federation, the self-governin ...
.
Throughout numerous 5-year species reviews from 1988 to 2013, this endangered classification has not changed.
This stems from the fact that large numbers of government conservation programs have been relatively ineffective in
delisting the species.
A significant challenge for Shasta Crayfish conservation is that while researchers know what type of food Shasta Crayfish consume, their exact nutritional requirements are unknown.
This presents a significant challenge for long-term
captive breeding programs. Furthermore, no
critical habitat
Critical habitat is a habitat area essential to the conservation of a listed species, though the area need not actually be occupied by the species at the time it is designated. This is a specific term and designation within the U.S. Endangered Spec ...
has been identified for this species.
However, there is optimism that Rock Creek could serve as a future safe haven for the Shasta Crayfish.
Relocation of Shasta Crayfish to a new safe haven in Rock Creek
A 20-year inter-agency initiative led by the
California Department of Fish and Wildlife
The California Department of Fish and Wildlife (CDFW), formerly known as the California Department of Fish and Game (CDFG), is a state agency under the California Natural Resources Agency. The Department of Fish and Wildlife manages and protect ...
(CDFW) found significant success in June 2019 as it relocated over 28 Shasta Crayfish to a rehabilitated section of Rock Creek,
Shasta County
Shasta County (), officially the County of Shasta, is a county in the northern portion of the U.S. state of California. Its population is 182,155 as of the 2020 census, up from 177,223 from the 2010 census. The county seat is Redding.
Shasta ...
.
The goal of this conservation effort was to create an isolated population of Shasta Crayfish that was inaccessible to the invasive
Signal Crayfish
The signal crayfish (''Pacifastacus leniusculus'') is a North American species of crayfish. It was introduced to Europe in the 1960s to supplement the North European ''Astacus astacus'' fisheries, which were being damaged by crayfish plague, but ...
.
As a result, this large-scale project necessitated considerable habitat modifications, such as riparian plantings and rock clusters. Likewise, a pipeline from CDFW's
Hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled condit ...
at
Crystal Lake Crystal Lake or Crystal Lakes may refer to:
Lakes
Canada
* Crystal Lake (Saskatchewan)
* Crystal Lake (Ontario), drain into the Lynn River, which drains into Lake Erie
United States
* Crystal Lake, California, a mountain lake in Nevad ...
had to be rerouted, and an upstream
diversion dam
A diversion dam is a dam that diverts all or a portion of the flow of a river from its natural course. Diversion dams do not generally impound water in a reservoir; instead, the water is diverted into an artificial water course or canal, which ...
had to be removed. The Hatchery's location is optimal since it prevents
Signal Crayfish
The signal crayfish (''Pacifastacus leniusculus'') is a North American species of crayfish. It was introduced to Europe in the 1960s to supplement the North European ''Astacus astacus'' fisheries, which were being damaged by crayfish plague, but ...
from migrating
upstream
Upstream may refer to:
* Upstream (bioprocess)
* ''Upstream'' (film), a 1927 film by John Ford
* Upstream (networking)
* ''Upstream'' (newspaper), a newspaper covering the oil and gas industry
* Upstream (petroleum industry)
* Upstream (software ...
and invading Rock Creek.
This restoration project was completed in collaboration with the
Pacific Gas & Electric Company (PG&E), the
United States Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...
, CDFW, and the consulting firm Spring Rivers Ecological Sciences LLC.
Today, the formerly dry portion of Rock Creek flows with around 0.6 miles of cool, clear water: a suitable
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
for the Shasta Crayfish.
After completing the Rock Creek restoration, scuba divers gathered Shasta Crayfish from the bottom of
Crystal Lake Crystal Lake or Crystal Lakes may refer to:
Lakes
Canada
* Crystal Lake (Saskatchewan)
* Crystal Lake (Ontario), drain into the Lynn River, which drains into Lake Erie
United States
* Crystal Lake, California, a mountain lake in Nevad ...
for relocation. Crystal Lake was chosen because it contains a genetically diverse and viable population of Shasta Crayfish that is most accessible to the CDFW. Following a 42-day quarantine, the divers relocated the crayfish to their new home in Rock Creek.
In the long term, the progress of these crayfish will be monitored closely by the CDFW with the hope that the population can sustainably grow without intervention.
References
External links
*
*
{{Taxonbar, from=Q3888507
Astacidae
Crustaceans of the United States
Endemic fauna of California
Freshwater crustaceans of North America
Crustaceans described in 1914
Critically endangered fauna of California
Taxa named by Walter Faxon
ESA endangered species