Lake NicaraguaCaroline Burdick, Sarah Heath, Jeremy Clothier, Alexandra Harding

Ecosystem Description

Geographic Location

 

19th largest lake in world

Largest in C. Am.

9th largest in Americas

Geologic History

● Ocean Bay => volcanic eruption = inland basin containing two lakes, linked by the Tipitapa River

● “The Great Lake of Nicaragua” until the level dropped to form the two lakes.

Subducting plate

Geography

Area:

Area: 3,149 square miles Length: 110 miles Average width: 36 milesDepth at center: About 60 feet Deepest point: 200ft

Geography

● More than 40 rivers drain into the lake

● Rio San Juan flows for 112 miles to the Caribbean Sea

● On west side, lake is separated by a 12 mile wide isthmus

● Punctuated by volcano islands

Physical and Chemical Characteristics

● Volcanic rocks at bottom of lake => dissolved Magnesium and Potassium salts

● Surface water temp- mid-70s ● Bottom temperature- low 60s

Seasonal and Annual Variation

Water level drops 2 feet (65cm) during dry

season (December to April)

Levels rise during rainy season (May-October)

●

Climatic Conditions

Tropical Savannah

Rainforest (disturbed)

Cloud Forest (Mombacho)

Ometepe Island

● 275 km2 area formed by volcanoes Concepcion and Maderas, connected by a low and frequently flooded isthmus.

● Ometepe- 15,000 population

Isla Ometepe

5301 feet (1616 meters) above sea level

Periodically ejects sand, ash and lava

Volcan Concepcion

Erupted more than 25 times in last 120 years. First recorded activity was AD 1883

Maderas

Maderas

Extinct, truncate volcano of 4377 ft (1334 m), covered with dense vegetation. Lots of coffee groves!

Zapatera Island

● Dormant volcano (2,064 ft- 629 m) with rocky coasts surrounded by semicircular islands, the remains of partially flooded craters

● “Mausoleum island” in pre-Spanish times

Las Isletas

North of lake=> Las Isletas (islets) form an arc-shaped rocky peninsula surrounded by islets- results of a massive avalanche torn off from volcano Mombacho

Anthropogenic Modifications

● Waste-water

● Agriculture● Cattle● Chemicals● Fertilizers

● Mining● Drought● Deforestation

● Just wait, THERE’S MORE….

General Description of Fish Habitats

● Bottom of lake= muddy regardless of depth

● Near Ometepe, rocky places

● Sandy bottoms SW of Ometepe (probably from recent eruptions)

Fish Species

Cichlids Galore

The Largetooth Sawfish

The Almost Nicaragua Bull Shark

Non-Native Fish

Fisheries of Lake Nicaragua

●

Historical Fisheries

● Mostly subsistence fishing

● No need for management

Then the 1970’s Happened

● Granada processing plant

● Let the games begin!

The 1980’s Bring Management

● Nicaragua Fisheries Institute

● Began regulating their fish resources

● Is now the National Fisheries and Aquaculture Administration

http://www.youtube.com/watch?v=cIme0-GTmqo

Movement Towards Aquaculture

● Now have a slightly more responsible mindset

● Aquaculture takes over

● Tilapia

Sportfishing

● Tarpon, snook, bass, machacas

● Regulations

● Tourism

Using Fish for Profit

● Sums up the attitude towards fish in the Lake

● Overall fish are secondary

Management and Conservation

Located in the Lake Nicaragua - San Juan River basin system, which does not fall into only one management area.

Management and Conservation

Some key players:

Ministry of Environment and Natural Resources (MARENA)-Nicaragua

Ministry of Energy, Resources, and Mines (MINAE) -Costa Rica

Current lake management practices include:

Tracking surrounding land use and monitoring of water quality.

Management and Conservation

Management and regulation of water resources in Nicaragua seem to be well defined in legislation, but there are issues with implementation.

Management and Conservation: Current and Future Issues

One HUGE issue stands apart from the rest:

The Nicaragua Canal

● A 173-mile trans oceanic canal that will cut through the lake

● Nicaraguan government signed agreement with Chinese company for the $50 billion dollar project

● Construction slated to begin on Dec. 22nd (this year!)

How it came about

It has come up before in the past, but never happened. This time it looks to be the real thing:

● The Nicaraguan government signed an agreement with a chinese company to construct the canal.

● Who is the person behind the chinese interest?

41 year old Wang Jing, a chinese billionaire

● Nicaragua agreed because they see this as an economic opportunity...but at what cost?

A few Details

● 174 miles long● 500+ yards wide ● A depth of 27.6 meters has been proposed● The canal would require an extensive lock

system requiring dams to be built.

What about the Panama Canal?

Oil Tankers in Already Threatened and Endangered Fish Habitat

Issues, so many Issues

● The lake is a major source of fresh drinking water to the country, also implications with clean water for fish

● Already threatened and endangered species in the lake. ● Bilge water from ships● Dams and construction in an area of high seismic activity.● Lock System ● History of volcanism. ● Potential for oil spills. ● Dredging and sedimentation issues ● Wetlands surrounding the lake● Potential for pollution input

Environmental Review?

Construction is supposed to start this month, but…

The full environmental review set to be carried out by a company called Environmental Resources Management may not be available until March.

Some Mitigation?

A few important mitigation measures mentioned at a recent meeting:

● Site in the port was changed to preserve mangrove swamps● Plan to use no explosives to dredge the channel through the lake

(they want to use another special technique for sediment removal) Impacts on fish?

● Environmental Resource Management has identified the island of Ometepe as an area of great biological importance.

● Route was changed to avoid the San Miguelito Wetlands

Future?

What will things look like in a few years? Further down the road?

We Don’t Know!

Fisheries will be changed forever.

Sources

● http://pubs.usgs.gov/of/2001/0457/● http://www.volcano.si.edu/volcano.cfm?vn=344111● http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1001&context=ichthy

nicar● http://www.elasmo-research.org/education/ecology/fresh-bull.htm● http://www.pri.org/stories/2012-01-07/nicaraguas-gold-mining-industry-boom

ing-boosting-countrys-economy● http://www.fsdinternational.org/country/nicaragua/envissues● http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1018&context=ichthy

nicar

● Koenig, Kurt W.; Beatty, Richard J.; and Martinez C., Sergio, "Species Diversity and Distribution of Fish in Lake Nicaragua" (1976). Investigations of the Ichthyofauna of Nicaraguan Lakes. Paper 19.

Sources

Other Sources–List of Cichlid species and care needs http://badmanstropicalfish.com/cichlid_of_month/Lake_Nicaragua.html

–Largetooth sawfish data http://www.nmfs.noaa.gov/pr/species/fish/largetoothsawfish.htm

–General informationhttp://vivatropical.com/nicaragua/lake-nicaragua/

Sources

Scholarly Sources–Tagging Study on Bull Sharks http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1037&context=ichthynicar&sei-redir=1&referer=http%3A%2F%2Fscholar.google.com%2Fscholar%3Fhl%3Den%26q%3DLake%2BNicaragua%2Bshark%26btnG%3D%26as_sdt%3D1%252C38%26as_sdtp%3D#search=%22Lake%20Nicaragua%20shark%22

–Study of Species Diversity and Distribution http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1018&context=ichthynicar

–Study of Cichlid Distribution http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1024&context=ichthynicar

Sources

● Lake Basin Management Initiative Experience and Lessons Learned Brief: Lake Cocibolca/Nicaragua

http://www.worldlakes.org/uploads/cocibolca_30sep04.pdf

● http://www.nature.com/news/conservation-nicaragua-canal-could-wreak-environmental-ruin-1.14721● http://www.npr.org/2014/02/20/279710270/scientists-fear-ecological-disaster-in-nicaraguas-planned-canal● http://www.npr.org/blogs/parallels/2014/08/14/340402716/nicaragua-banks-on-its-own-canal-to-boost-economy● http://www.telegraph.co.uk/news/worldnews/centralamericaandthecaribbean/nicaragua/10952824/Nicaragua-app

roves-route-for-23bn-rival-to-Panama-Canal.html● http://www.telegraph.co.uk/news/worldnews/centralamericaandthecaribbean/nicaragua/11167697/Giant-canal-thr

eatens-way-of-life-on-the-banks-of-Lake-Nicaragua.html● https://play.google.com/books/reader?id=ss5IAAAAMAAJ&printsec=frontcover&output=reader&hl=en● http://www.worldlakes.org/lakedetails.asp?lakeid=8934● http://media.economist.com/sites/default/files/cf_images/19980822/cam573.gif● http://insidecostarica.com/2014/11/28/nicaragua-hknd-plan-mitigate-environmental-impact-canal● https://www.youtube.com/watch?v=xtn3jgsDqUc

Sources

● Lake Nicaragua Fishery Resources WILLIAM D. DAVIES, university of Nebraska-lincoln http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1015&context=ichthynicar

● Tilapia (Teleostei: Cichlidae) status in Nicaraguan natural waters, http://www.gaianicaragua.org/EBF2007TILAPIA.pdf

● Food and agriculture department of the united nations: fisheries and aquaculture, http://www.fao.org/fishery/countrysector/naso_nicaragua/en#tcN70085

● San Carlos Sport Fishing, http://www.nicaraguafishing.com/english%202.htm

Sources

● Sport fishing regulations, https://vianica.com/activitydetails/150/sport-fishing-in-rio-san-juan

● Personal perspectives on gill netting in lake Nicaragua, http://www.nicaragua-community.com/past-present-potential-future-fishing-isletas-granada/