Conservation Biology Midterm 2

3 Goals of Conservation Biology

Document biodiversity.

Examine human impact on living systems.

Prevent the extinction of species, maintain biological diversity, and restore biological communities and ecosystem functions.

Primary Influences of human impact on living system

Habitat destruction, habitat fragmentation, habitat degradation, global climate change, over-exploitation, invasive species, disease

Habitat Destruction

Primary cause of biodiversity reduction. 98% of the land suitable for agriculture has already been transformed.

Farmers will need to increase output by 30-50% in the next 30 years to support the growing population

what % of Earth's surface has not been modified by humans

25%

Threatened Habitats: Tropical Deciduous Forests

Suitable for agriculture and cattle ranching - nutrient retention

Threatened Habitats: Grasslands

Easy to convert - farmland and cattle ranches

Threatened Habitats: Freshwater Habitats

Ecosystem functions and services are lost.

Dams, channelization of watercourses, chemical pollution

Threatened Habitats: Marine Coastal Areas

Pollution, dredging, sedimentation, invasive species, rising temperatures

Threatened Habitats: Mangroves

Important economically - commercial fisheries

Protection from storm surges

40% of mangrove-dependent species are at high risk of extinction

Threatened Habitats: Coral Reefs

20% destroyed.

20% degraded - overfishing, overharvesting, pollution, invasive species

The Problem with Palm Oil

90% of the world's palm oil production occurs in Malaysia and Indonesia

Sumatran Tiger

Only 400-600 are left in the wild.

From 2009-2011, 2/3 of the habitat was cleared for Palm oil plantations

Habitat Fragments differ from the original habitat in 3 important ways

Fragments have a greater amount of edge per area of habitat.

The center of a habitat fragment is closer to an edge.

When a formerly continuous habitat hosting a large population is divided into fragments, each fragment hosts a smaller population.

Threats from Habitat Fragmentation

• Limits to dispersal and colonization

  • Agricultural fields, roads

• Restricted access to food and mates

• Creation of smaller populations

  • inbreeding depression, genetic drift

• Interspecies interactions

  • Increases chances of nonnative species

  • Wild and domestic animal interactions

• Edge effects

  • Changes in light, humidity, temperature, and wind

Florida Panther

Intersected by highways

Public land

Private land

Pollution

Most widespread form of habitat degradation

Types of pollution

Pesticides

Oil Spills

Toxic Metals

Eutrophication

Acid Rain

Pharmaceuticals and Personal Care Products (PPCPs)

Plastics

Oil Spills

Direct exposure and toxicity

Indirect exposure from clean up

Disproportionate impact on biodiversity (intertidal vs. pelagic)

Toxic Metals

Mining

Leaded gasoline

Burning of coal (heat and power)

Disposal of electronic waste

Biomagnification

Eutrophication

Release of high amounts of nitrates and phosphates into aquatic systems

Dense growth of plant life and death of animal life from a lack of oxygen

Eutrophication

The process by which a body of water becomes enriched in dissolved nutrients (as phosphates) that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen

A c i d R a i n

Release of nitrogen and sulfur oxides into the air

Combine with moisture to create nitric and sulfuric acids, which lowers the pH of rainwater

Weaken and kill trees

Leach soils of nutrients (K* and Ca?+) needed for plant growth

Increased acidity in bodies of water

PPCPs

Medicines used by people and livestock

Personal health or cosmetics

Discharged directly into surface waters or into plumbing and sewer systems

Plastics

Entanglements

Ingestion

Don't biodegrade

Can photo-degrade into smaller particles = Microplastics (<5mm)

Who is Wisdom?

The legendary Laysan albatross or möli, the oldest confirmed wild bird in the world and the oldest banded bird in the world. First tagged in 1956 at Midway Atoll by the United States Geological Survey, she was still incubating eggs as late as 2025

Disease

High rate of contact between host and pathogen or parasite encourages the spread of disease

Indirect effects of habitat destruction can increase an organism's susceptibility to disease

Infectious diseases can spread between wildlife populations, domestic animals, and humans as a result of increasing human densities

What put Black Footed Ferrets at risk?

Habitat destruction and fragmentation

Reduced population sizes from habitat loss and fragmentation

Proximity to humans and domestic animals

What put endemic Hawaiin birds at risk?

Invasive mosquitoes have introduced malaria into the populations

White Nose Syndrome

A fungus that attacks bats while they are hibernating, disrupting hibernation and may cause starvation or dehydration. Putting the North American Bats at risk

Zoonotic Diseases

Diseases that arise from animals and then can infect humans

Commercial: Fishing

360 billion worldwide; 171 million metric tons

Wild-capture fisheries - 53% of total, $131 billion

Aquaculture - 47%; $232 billion

Maximum Sustainable Yield

Assumption: population growth is fastest at K/2 (half of carrying capacity) and most sustainable

Carying Capacity

The maximum number of individuals of a particular species that an environment can sustainably support over a long period

Totoaba

a critically endangered fish found in Mexico, harvested for their swim bladder 

Vaquit

(small endangered Mexican porpoise)

Caught in a commercial net

Current Population estimated to be 10 individuals

The Mexican government has currently opened up the main vaquita habitat for fishing.

Illegal Wildlife Trade

$7-23 billion / year

Pangolins

One million animals trafficked between 2000 and 2013

1270 seizures reported from 67 countries across 6 continents

159 unique trade routes

27 new routes a year - evading authorities

Subsistence: Bushmeat

Meat from non-domesticated mammals, reptiles, amphibians, and birds hunted for food in tropical forests

Recreational Hunting

Recreational hunting is a major component of wildlife management in North America

$34 billion on trips, equipment, and licenses

Recreational Fishing

47 billion fish/year globally

3 Major types of species responses to changing climates

Space

Time

Self

Changes in Space

Species will shift their distributions to stay within their optimal conditions.

Shifts will largely be toward higher latitudes (polewards) and to higher elevations.

Changes in Time

Animals: Changes in migration and hibernation dates. Activity times.

Plants: Changes in flowering and fruiting times; length of growing season.

Changes in “self”

Acclimation (change within a generation)

Adaptation (change across generations; genetic), physiological morphological carry-over, genetic effects (trait suites)

Spectacled flying fox populations

One third of Australia's spectacled flying foxes died in an extreme heatwave north of Cairns in November 2018

Piping Plover

Increased abundance in New York as a result of Hurricane Sandy (2012)

Biological Control: Cane Toad

Introduced to Hawaii and Australia in 1935 to control beetles.

Biological Control: Mongoose

Introduced to Hawaii in 1883 to control rats

Acclimatisation Societies

encouraged the introduction of non-native species to enrich the flora and fauna of a region

Threats from Invasive Species

1 . Competition for resources

2 . Predation and parasitism

3 . Changes in ecosystem processes

4 . Alteration of abiotic conditions

What makes a species invasive

1 . Thrive in disturbed habitats

• Non-native or native

2 . Predator release hypothesis

• Able to thrive because of the absence of the specialized natural predators and parasites that would otherwise control growth

3 . Genetic swamping - hybrids between native and invasive, where unique genotypes may be erased and taxonomic boundaries are obscured