Temperature

Temperature Average kinetic energy of a system Arguably the most important aspect of the physical environment for life Influences geographic distributions of species Influences interspecific competition

For most living, active animals: Temperature Ranges For most living, active animals: -2 °C (polar aquatic species) to 50 ° C (desert spp.) Few species can survive entire range

Terminology of Thermal Biology Various terms used to describe thermal biology of animals: Cold-blooded vs. Warm-blooded Poikilothermic vs Homeothermic Ectothermic vs. Endothermic

Cold-blooded vs. Warm-blooded Description of relative body temperature “Warm-blooded” = high body temperature Mammals and birds “Cold-blooded” = low body temperature Reptiles, amphibians, fish, invertebrates Tend to be inaccurate Many “cold-blooded” animals have high body temperatures (e.g. desert reptiles and invertebrates) Many “warm-blooded” animals may have low body temperatures (e.g. hibernating mammals)

Homeothermic vs. Poikilothermic Description of variation in body temperature Homeothermic – body temp. strictly regulated Mammals and birds Poikilothermic – body temp. may fluctuate widely “Lower” vertebrates and invertebrates Problems Many “poikilotherms” normally have stable body temperatures under natural conditions Some “homeotherms” have broad seasonal changes in body temperature (hibernation, etc.)

Endothermic vs. Ectothermic Description of heat production Endothermic – most body heat is physiologically generated (muscle contraction) Ectothermic – most body heat derived from the environment (solar radiation, etc.) Problems Some animals generate lots of heat but do not use it to regulate body temperature

Determinants of Body Temperature Temperature depends on the amount of heat (calories) contained per unit mass tissue # calories contained per °C determined by the heat capacity of the tissues (~ 0.8 cal*°C-1*g-1) Amount of heat in body depends on… Rate of heat production Rate of external heat gain Rate of heat loss to the environment Body heat = heat produced + heat transferred

Heat Transfer Three ways of transferring heat Conduction – transfer of heat between objects in contact with one another Radiation – transfer of heat by electromagnetic radiation Evaporation – transfer of heat to water as it changes from liquid to gaseous phase

Conduction Transfer of kinetic energy between two objects in contact Heat moves from warmer region to cooler region Rate of transfer: H = rate of heat transfer per cross sectional area k = thermal conductivity of the conductor d = distance between two points T1 and T2 = temperature at points 1 and 2 H = k × T1 – T2 X

Conduction and Convection Conduction rate is increased by convection Movement of gas or liquid over the surface of transfer Continuous replacement of fluid maximizes temperature difference and facilitates heat transfer

Radiation Transfer of heat via electromagnetic emission Objects do not require contact Stefan-Boltzmann law: H = εσTs4 H = rate of heat exchange per unit area ε = emissivity (wavelengths at which EM radiation is emitted,~3-4 μm for most objects on earth) σ = Stefan-Boltzmann constant Ts = surface temperature of the object Net heat exchange is from the object with the higher Ts to the one with the lower Ts

Evaporation Only means by which heat can be lost to a hot environment Vaporization of water requires heat ~ 2400 kJ per g water absorbed from the surface of the animal Evaporative cooling used to dissipate heat Sweating, panting

Heat Storage Animals can store heat in their bodies by moderating heat transfer to the environment Factors Affecting Heat Transfer Surface Area/Volume Ratio Larger animals have proportionately lower heat flux Temperature Gradient Between body and environment Lower gradient, slower heat transfer Specific Heat Conductance Insulation – reduces heat conductance

Total Body Heat Htotal = Hv + Hc + Hr + He + Hs Hv = heat produced by metabolism (+) Hc = heat loss/gain by conduction and convection (+/-) Hr = heat transfer via radiation (+/-) He = heat loss by evaporation (-) Hs = stored heat (+)

Effects of Body Temperature Change Temperature affects the rate of chemical reactions Affects chemical reactions needed to maintain homeostasis Too low metabolism not fast enough to maintain homeostasis Too high reactions in metabolic pathways uncouple, enzymes denature, etc.

Changes in Metabolism with Body Temperature Temperature Coefficient (Q10) – factorial increase in a rate with a 10 °C increase in temperature Q10 = (R2/R1) 10/T2-T1 R2 and R1 reaction rates at temperatures T2 and T1 respectively If T2 and T1 differ by 10 °C, Q10 = (R2/R1) Typical Q10 values for biological rates (metabolic rate, etc) range from 2 to 3 (doubling or tripling of rate)

Changes in Metabolism with Temperature Q10 values often change across a range of temperatures Performance curves Initial large increase, followed by smaller increases

Light

Effects of Artificial Light: - Orientation and Attraction/Repulsion - Reproduction - Communication - Competition - Predation - Ecosystem disruption

Complex Ecosystem

Effects of Artificial Light Living things respond in a variety of ways to impacts on the environment. Some examples of the effect of light at night are well known - moths gathering around a street lamp, or the harvesting of fish with spotlights. These changes can have a dramatic effect on humans - as for example the negative impact of light at night on the salmon fishery.

Terrestrial Mammals

Terrestrial Mammals Possible effects: - disruption of foraging behaviour - increased risk of predation - disruption of biological clocks, affecting mating success and group-mediated anti-predator vigilance - increased road deaths due to blinding and disorientation - disruption of dispersal movements and corridors Increased highway lighting is not effective in reducing deer-car collisions.

Terrestrial Mammals Many mammals (small carnivores, rodents) are nocturnal. These are affected by light at night. Night-adapted animals have a rod-based retina, which provides the necessary sensitivity for night vision but blinds the animal in bright light. Light (moonlight) increases the risk of predation, so small mammals stay hidden. A light level of 0.2 lux was sufficient to suppress melatonin production in rats and enhance tumor production.

Bats

Bats Insects are attracted to lights, bats then gather in the lights to feed on these insects. Moths evade bats by detecting their ultrasound, but moths do not use this warning in bright light, so they are an easy target.

Bats pipistrelle bats, who feed at streetlights In several mountain valleys in switzerland, the lesser horseshoe bat became locally extinct after streetlights were installed. They were replaced by pipistrelle bats, who feed at streetlights

Migrating Birds

Migrating Birds

Migrating Birds Migrating birds tend to move toward light and are reluctant to leave the lighted area. - delays migration - mortality due to exhaustion and collision with structures. Floodlit structures attract and kill birds, particularly in misty weather.

Sea Turtles

Sea Turtles Hatching turtles are disoriented by artificial light, causing them to go inland instead of to the sea. Artificial light also aids predation of the hatchlings. A number of measures have been taken with some success. These include shielding of luminaires, reducing light output, installing motion detectors and light curfews, and LED lighting embedded in roadways. All coastal buildings must now have a lighting plan. However, problems continue with population growth and lighting further inland that creates sky glow. Local lighting controls are not a complete solution.

Reptiles Gecko

Reptiles Rattle snakes and water snakes hunt in the dark of the new moon. These species have declined in areas of heavy light pollution. Gecko mating is curtailed in artificial light.

Frogs and Toads

Frogs and Toads Frogs and toads have extremely sensitive night vision, and can see in light levels of 10^-6 (10000000) to 10^-5 (1000000) lux. (Moonlight is typically about 1 lux). They are nocturnal, so light at night affects them and their predator-prey relationship. Some species are attracted to light, which acts as an 'evolutionary trap'. Mating behaviour (chorusing) and fertility (in toads) are inhibited under artificial light. After exposure to bright light (along a highway, for example) frog night vision can take hours to restore to night vision sensitivity.

Salamanders Newt

Salamanders Salamanders are aquatic animals. Newts rely on the day-night transition to initiate foraging, and rely on the characteristics of natural light for navigation. Artificial light interferes with both these activities, and may be one factor in their population decline.

Fishes Sea Trout

Fishes Some fish species are attracted to light, and fishing vessels use high-intensity lamps to attract their prey. Mercury-vapour lamps have been used to attract fish into special channels around dams and power stations. Other fish species avoid light. In Scotland, lights from a tennis court eliminated sea trout from a nearby river.

Fishes Juvenile rainbow trout are inhibited from foraging by moonlight or artificial light. Darkness is essential for fish to avoid predation. Harbour seals have learned to use artificial light to outmigrating smolts. Salmon fry are inhibited from migration by light levels in excess of 1 lux. Several species are inhibited from spawning (laying eggs) by light at night

Insects and Streetlamps Insects are critically important as pollinators and members of food webs in an ecosystem. Lamp Effects on beetles, moths, flies, caddisflies: Fixation or Capture Insect cannot escape near zone of the light. Crash Barrier Flight path is interrupted so insects cannot migrate Vacuum Cleaner Insects are removed from the area local to the lamp.

Insects and Streetlamps

Insects and Streetlamps Radius of attraction: 400 to 600 metres under full darkness, 40 to 60 metres under full moon. In dark zones, the attraction has been 2000 to 11000 insects per night. In a rural village with lighting, 400 to 1600 insects per night per lamp. Approximately 1/3 of the insects are killed or incapacitated. In order, worst to best, are high-pressure mercury, high-pressure sodium and low-pressure sodium lamps. Insect attraction can be reduced with a UV filter.

Insects and Streetlamps Mayflies

Moths

Moths Areas around artificial lights function as bat, bird, gecko and spider feeding stations. Some bats live only a few days, so any disruption of their behaviour has an effect on the population. Light interferes with dispersal, which inhibits resistance to habitat fragmentation. Light greater than 0.05 lux inhibits mating in one species of moth.

Moths Lamp with ultraviolet component (mercury vapour, LED) is a strong attractant. Low pressure sodium vapour rarely attracts moths. Individual lamps attract more strongly than an aggregate of lamps. One lamp trap collected 50,000 moths in a single evening. A typical catch rate is 4 to 10,000 insects per year. Artificial light can inhibit moth parasites.

Fireflies Artificial light swamps the luminescent mating communications of fireflies. Continuous light (due to skyglow) may affect the timing of development from pupa to fly. Artificial light inhibits the resettlement of fragmented habitat (light barrier effect).

Freshwater Habitats Plankton Daphnia

Freshwater Habitats Zooplankton are at the bottom of the food chain, so their health impacts the marine ecosystem. Nocturnal marine organisms respond to light of full moon (0.05 to 0.1 lux). Zooplankton rise to the surface at night. Artificial light suppresses zooplankton migration. Cued by low light, stream insects (eg, caddisfly larvae) migrate downstreamat night while foraging.

Plant Responses to Artificial Lighting

Plant Responses to Artificial Lighting There are four photoreceptor families. These have different spectrum responses in order to control the timing of growth (eg, germination) under various conditions (direct sun, open sky, shade). Photoperiodism: some plants are sensitive to the length of the day. Daylight extension inhibits the flowering of some plants and encourages it in others. A brief exposure to light will inhibit the cockleburr from flowering. Some trees exposed to lighting exhibited late season growth followed by severe winter dieback. Security lighting around prisons prevents soybeans from growing, within 30 metres of the source.

Minimizing the Impact of Artificial Light on an Ecosystem Turn lights off when they are not needed Reduces the impact on nocturnal insects, animals and on plants. Limit the extent of lighting Minimizes environmental impact and sky glow Use new lighting methods: Example: buried LED lamps in coastal highway Consider the impact of spectrum Example: some insects are particularly sensitive to ultraviolet

Water pollution effects

State of water Natural Water has, Physical attributes ( Temperature, smell, Colour ) Chemical attributes – pH, DO, ions Biological attributes – microorganisms Organisms and users will adapt to water with particular physical, chemical and biological attributes Salty sea Fresh Water Water Pollution Alteration of the water features/attributes to the detriment of its inhabitants and users

State of water cont; Water Quality The degree of pollution from the point of view of organisms living in or using the water. Pollution Sources Point sources Piped (sewage,oils) Stormwater drains Non- Point sources Agricultural runoff Atmospheric pollution Seepage from mine/urban areas

What is water pollution ? "Water pollution" is defined as the addition of harmful or objectionable material causing an alteration of water quality.

How does water pollution occur? Mankind through socio-economic activities introduce pollutants to the environment. “Then the Earth’s waters cycle, carry and spread the pollutants all around the planet.”

Water Cycle Ocean runoff Water Supply Salt Water Intrusion Aquifer Evaporation Evapo-transpiration runoff Water Supply Discharge treated water Salt Water Intrusion Aquifer Infiltration Recharge Extraction Precipitation Evaporation/ET Surface Water Groundwater Soil moisture Infiltration (Art) Return flow Treated water Aquifer intrusion Soil moisture

Pollution types Thermal Pollution (Heated factory water or cooler water from another basin) Warmer …less dissolved Oxygen Cooler …More dissolved Oxygen Suspended solids (Silts, Clay, living organisms, dead organic Matter). Dissolved solids (chemicals) Acid rain water (Nox and sox) Leaching effects Trace elements (Heavy Metals)

Human activities that contribute to water pollution Overgrazing Poor agricultural land management Removal of riparian vegetation Sewage, industrial, and domestic discharges Construction, Mining Release of gases and aerosols to the atmosphere Mismanagement of reservoirs Accidental spills

Water pollutants (polluting elements) Sewage/waste water; Fertilizers/Pesticides; Alien species Global Warming Atmospheric Deposition; Pathogens; from untreated sewage, storm drains, septic tanks, runoff from farms Petroleum; Radioactive substances; Heat; Siltation/sediments; Salinization - Increased salinization and salt runoff from irrigated farms causes salinization of major rivers; Heavy metals cause unpleasant taste and odour to drinking water; Suspended particles like sediments

Effects of polluted water on; Effects on Agriculture; - use of wastewater and polluted surface and groundwater which contaminate crops and transmit disease to consumers and farm workers; Depositions of deleterious chemicals in soil leading to loss of soil fertility; 2. Effects on Environment/ecosystems; - pungent smell, discolourisation; increased temps; contamination; change the pH; decreased oxygen; detergents that create a mass of white foam in the river waters; Enrichment of groundwater with salts, nutrients from irrigated lands; eutrophication/algal blooms-what is the effect on recreational activities, water treatment plants/water providers; loss of aesthetic value; Algae clogs our waterways

Effects of polluted water on; 4. Domestic effects; - toxic substances such as lead, mercury, cadmium, and chromium or cyanide, which may affect the use of the receiving water for domestic use or for aquatic life. 5. Effects on industry; boiler scales, Heavy metals cause unpleasant taste and odour to drinking water; Suspended particles cause unpleasant taste & discoloration to drinking water;

Effects of polluted water on; 6. Economy Unsightly color, reduced clarity, and obnoxious odour of the receiving waters also make it unfit for recreation and other productive uses; Adverse effects of water pollution lead to economic losses in terms of reduced health, reduced agricultural productivity, and low-quality tourism. There is also economic losses to family income due to the desire for safe bottled water which is more expensive than unbottled water. When water is polluted, fish and other aquatic resources can perish, which leads to a decline in fisheries production. Erosion from degraded uplands and pollution from silt and sedimentation, as well as untreated sewerage, cause productivity losses in fisheries. Silt and sedimentation are major causes for losses in fishery production. High levels of turbidity leads to economic losses;

Effects of polluted water on; Improvement of water quality- Removal of organic matte thru aerobic decomposition; chlorination to remove bacteria, suspended solids; precipitation of salts, desalination etc during water treatment is expensive for polluted water; Increased salinization and salt runoff leading to salinization of major rivers.; Heavy metals cause unpleasant taste and odour to drinking water; Suspended particles cause unpleasant taste & discoloration to drinking water;

Effects of polluted water on; Hard water with usually high levels of calcium and magnesium can cause a build-up of minerals in pipelines/boiler scales and cause erosion and blockage problems. Water softeners and conditioners can be used in the water to reduce limescale but can be expensive.

Effects of polluted water on; 7. Leisure Swimming pool water can become contaminated with a number of different pollutants and may cause changes in water colour and odour, some pollutants may also be harmful to human health. Discolouration of the swimming pool water could be due to a number of reasons. It may be dirty and cause the water to change a milky colour if the filter is inadequate or blocked. Algae contamination can also cause discolouration, black algae cause black spots to appear in the pool. Other forms of algae contaminate pools when chlorine levels are too low, these often turn the water a green colour. Chlorine is used in many swimming pools to keep them clean. There are certain substances, such as certain types of detergents and some forms of make-up, that don’t mix well with chlorine. These can cause adverse effects to human health such as skin and throat irritations. Pond water can also become polluted with different chemicals or microbes. This can make the pond less attractive and can be harmful to aquatic life within the pond. An overgrowth of algae and accumulation of leaf debris are often the main problems with ponds in the home; UV filters are efficient at reducing algae levels in ponds and also remove decaying vegetation. These are useful for long term maintenance of your pond.

Effects of polluted water on; 8. Effects on human health; Increased incidence of tumours, ulcers due to nitrate pollution; Increased incidence of skin disorders due to contact with pollutants; Increased incidence of constipation, diarrhea, and infections to intestine; Dangerous effects on growing foetus in pregnant women; Concentration of pollutants due to bioaccumulative pesticides through secondary and tertiary food chains in case of non-vegeterians; Still births, abortions, and birth of deformed children; Blue baby disease caused by methaneglobinema-which results in asphyxia (reduced oxygen supply);Reduced activity of immune system; Loss of memory power and reduced mental sharpness; Water borne diseases like jaundice, hepatitis, gasteroenteritis, will be more prevalent due to water pollution; Reduced bone development and muscular development; Reduced male fertility; Shifts in physiological cycles of human body.

Effects of polluted water on; 9. Effects on animal health; Large scale death of aquatic and terrestrial animals; Reduced reproduction rate; Increased disease incidences; Imbalances created in secondary foodchains; Accumulation of bioaccumulative and nonbiodegraddable pollutants in animal bodies; Bioaccumulation eg of organochlorine pesticides; Biomagnification; Cause health hazards like impotence, cancerous tumours etc

Major water related diseases Type Diseases Cause Effects Prevention 1 Water borne (Disease causing vector carried in water) Cholera Typhoid Diarrhoea Dysentery Drinking contaminated water Eating contaminated food Dehydration Use clean water for drinking Keep flies away from food Avoid unprotected water sources 2 Water washed (Resulting from lack of water or improper use of water) Scabies Eye infections Not washing Lack of enough water for washing Itchy lashes Sore eyes Blindness Fever from lice diseases Increase water availability for washing Improve personal hygiene 3 Water Based (Vector lives in water) Bilharzias Worms from the snails enter through the skin in infected water Blood in stool Pain in stomach Reduce contact with infected snails Control snails 4 Insect vector related Malaria River blindness Mosquitoes bites Semolina worm Fever Aches Removal potential larvae breeding sites Use mosquito netting Introduce fish in ponds river water