SALINITY & OSMOREGULATION HOW DOES SALT IMPACT THE ORGANISMS THAT LIVE IN IT? KL OCEANOGRAPHY UNIT II: OCEAN PLANET

OCEAN SALINITY SALINITY= # OF GRAMS OF A DISSOLVED SALT IN 1 KG OF OCEAN WATER MEASURED IN PARTS / THOUSAND OR PPT OR ‰ AVERAGE SALINITY OF OCEAN WATER = 35‰ MAJOR TYPES: NACL (SODIUM CHLORIDE) KCL (POTASSIUM CHLORIDE) MGCL 2 (MAGNESIUM CHLORIDE)

OCEAN SALINITY SOME SOURCES OF SALT: VOLCANIC ACTIVITY  CHLORINE GAS AND SULFUR EMITTED  CL- IONS EROSION & RUNOFF IN THE MOUNTAINS (WEATHERING)  NA+, MG+, K+ IONS WAVES & EROSION ALONG THE COAST  VARIOUS SALTS CREATED BY ERODING BASALT AND LIMESTONE IS SALINITY CONSTANT? NO! WHERE RUNOFF ENTERS FRESH WATER (ESTUARIES)  DILUTES IT (LOWER SALINITY) EVAPORATION (SHALLOW WATER BODIES)  INCREASES SALINITY  CONCENTRATES THE AMOUNT OF SALT

SOURCES OF SALT

WATER & CELL MEMBRANES WATER FACILITATES CHEMICAL REACTIONS BOTH OUTSIDE OF AND WITHIN LIVING SYSTEMS THE JOB OF THE CELL MEMBRANE IS TO KEEP THE CONTENTS OF THE CELL SEPARATE FROM ITS ENVIRONMENT. CELL MEMBRANE IS MADE OF PHOSPHOLIPIDS THAT ARE POLAR MOLECULES HEADS ARE POSITIVE TAILS ARE NEGATIVE

WATER & CELL MEMBRANES POLAR MOLECULES ATTRACTED TO WATER ARE HYDROPHILIC(WATER LOVING). LIKE THE “HEADS EX>SPONGE NONPOLAR MOLECULES/SUBSTANCES THAT CANNOT ATTRACT WATER ARE HYDROPHOBIC (WATER FEARING). LIKE THE “TAILS” EX> WAX

OSMOREGULATION ISOTONIC SOLUTION ISOTONIC SOLUTION- SOLUTIONS HAVE SAME CONCENTRATION OF SOLUTE HYPERTONIC SOLUTION HYPERTONIC SOLUTION- HIGHER CONCENTRATION OF SOLUTE (MORE MOLECULES) HYPOTONIC SOLUTION HYPOTONIC SOLUTION- LOWER CONCENTRATION OF SOLUTE (LESS MOLECULES ) OSMOREGULATION= REGULATING THE AMOUNT OF WATER IN THE CELL THROUGH OSMOSIS AS A CELL RESPONDS TO OTHER DISSOLVED SUBSTANCES IN ITS ENVIRONMENT (LIKE SALINITY FLUCTUATIONS). OSMOSIS= MOVEMENT OF WATER INTO AND OUT OF THE CELL MEMBRANE

ISOTONIC SOLUTION ISOTONIC=SAME AMOUNT OF SOLUTE INSIDE THE CELL AS IS IN THE SOLUTION ITS IN HAVING EQUAL OSMOTIC PRESSURE AS THE COMPARISON SOLUTION. SAME AMOUNT OF WATER FLOWS INTO AS FLOWS OUT OF THE CELL

HYPOTONIC SOLUTION HYPOTONIC= GREATER CONCENTRATION OF SOLUTE INSIDE THE CELL, THAN OUTSIDE THE CELL CELL HAS A HIGHER OSMOTIC PRESSURE (INTERNALLY) THAN A COMPARISON SOLUTION OSMOTIC (TURGOR) PRESSURE- FORCE EXERTED ON THE MEMBRANE/WALL HIGH OSMOTIC PRESSURE CAN CAUSE CYTOLYSIS-WHICH IS THE BURSTING OF CELL MEMBRANES

HYPERTONIC SOLUTION HYPERTONIC= A GREATER CONCENTRATION OF SOLUTE OUTSIDE THE CELL, THAN INSIDE THE CELL. CELL HAS A LOWER OSMOTIC PRESSURE (INTERNALLY) THAN A COMPARISON SOLUTION LOW TURGOR PRESSURE CAUSES PLASMOLYSIS, WHICH IS “CELL SHRINKING”. CAUSES PLANTS TO WILT

OSMOREGULATION ORGANISMS ARE EITHER: OSMOCONFORMERS- DO NOT HAVE ADAPTATIONS TO HELP REGULATE SALT OR OSMOREGULATORS- HAVE SOME SORT OF ADAPTATION TO MAINTAIN OSMOTIC BALANCE

OSMOCONFORMERS OSMOCONFORMERS= ANIMALS WHOSE INTERNAL OSMOTIC CONCENTRATION IS THE SAME AS THE SURROUNDING ENVIRONMENT. MOST MARINE INVERTEBRATES NEED TO STAY WHERE THE SALINITY OF THE WATER MATCHES THAT OF THEIR BODY FLUIDS, OR ELSE THEY COULD SWELL AND BURST (IF PLACED IN FRESHWATER).

OSMOREGULATORS OSMOREGULATORS= ANIMALS THAT MAINTAIN AN OSMOTIC DIFFERENCE BETWEEN THEIR BODY FLUID AND THE SURROUNDING ENVIRONMENT. MARINE BONY FISH THEY HAVE SPECIALIZED KIDNEYS HELP THEM RETAIN WATER BY PRODUCING CONCENTRATED SALTY URINE. MARINE REPTILES DO INGEST SEA WATER FOR NUTRIENTS DO HAVE SALT GLANDS THAT EXCRETE THE EXCESS SALT

OSMOREGULATORS MARINE MAMMALS DO NOT INGEST SEA WATER  DUE TO DEHYDRATION. THEY DO HAVE HIGHLY EFFICIENT KIDNEYS THAT PRODUCE VERY SALTY, CONCENTRATED URINE. OBTAIN FRESH WATER FROM CELLULAR RESPIRATION AND FROM FEEDING ON FISH AND INVERTEBRATES. CARTILAGINOUS FISHES DO NOT HAVE SPECIALIZED KIDNEYS LIKE FISH DO PRODUCE A CHEMICAL CALLED UREA IN THEIR BLOOD THAT THEY REGULATE THE AMOUNT OF WATER IN THEIR CELLS. DO HAVE AN EXCRETORY GLAND CALLED THE RECTAL GLAND THAT ELIMINATES EXCESS SALT.

OSMOREGULATION IN SHARKS

OSMOREGULATION IN MARINE FISHES

OSMOREGULATION IN FRESH WATER FISHES