Question

Aa Bbccdee Aa Bbccdee AaBbCcDc AaBb code AaB No Spacing At a global scale, harmful algal blooms (HABs) are appearing in many places, often new places, and lasting longer than previously recorded. Across Florida, the occurrence of algal blooms, caused by various species of phytoplankton, has been intensifying. In the summer of 2016, a state of emergency was declared because a toxic cyanobacterial bloom occurred in Lake Okeechobee which spread into and throughout the St. Lucie River and Estuary. Water samples collected during the bloom helped identify a limiting nutrient. 1. Data from a Burger et al. (2004) indicate that mercury levels in Florida gar, top-level predators, from Lake Okeechobee were not higher than mercury levels of fish muscle from other locations in the United States. However, mercury levels in the livers of Florida gar were above the level considered safe for human consumption. a. Explain why this is good news for people who fish in Lake Okeechobee. (1 pt) b. Explain why this is bad news for non-human consumers of fish, and how it might be bad news for the ecosystem as a whole. (2 pts) 2. In July 2017, the “dead zone" in the Gulf of Mexico was the size of New Jersey (NOAA 2017). a. Explain why the "dead zone" exists in the Gulf of Mexico. (1 pt) b. Hypothesize two reasons why the "dead zone" is at peak size in the summer and shrinks in the winter. (1 pt)

please help with some deeper thinking biology questions.

Answer 1

It's a good news for people who tis in Lake Okeechobe because the mercury level has been estimated in - Florida gar, and result is satis factory The reason is that nectado contaminants or bioaccumulative met als like mercury tend to accumulate in higher levels in the organisms occupying higher trophic level. This i biomagnification. As florida gar is top level predator and - the mercury levels in fish muscle collected - from Lake Okeechobe are in safe limits So it is sate to fish in this lake. (fishes occupying lower trophic levels than tlarida gar will have even lower levels of mercury). Mercury levels any how in take okee Chobe are lower than other locations in the United States so thats also a hatisfactory news. SteamScanner

0.5 ug Igrom Mercury level in liver of Flowe r was found over 0.5 on an average :) 0.5 mm l gran tgram sute for human consumption but the level is above this value to Florida gar so the non human consumers of fish are at nisk because consuming whole fish . ensure consumption of unsate levels of mercury Ecosystem I will suffer due to higher mercury levels because will make it way in food chain o the amount will thercase due to biomagnification. Higher levds of mercung will eventually cause mercury looisoning in humans and abo because the compounds of mercury such as methel mercury will be in higher amounts in fishes on top of food chain. Consumpton o unsate levels of mercing will be deleterious to all organisons eventually damaging ecosystem. Scanned with CamScanner

forms due to in and phosphorus og roin water flow. phosphorus of (a) The dead zone forms a accumulation of nitrogen as in streams and rivers by rain That The nitrogen and phosp come from fertilizers. The of rivers and streams le of algae Calgal blooms) and ul there is defaletion of oxygen to low oxygen the aquatic is threatened drastically. The enrichment o growth ultimatly -algal blooms) and - 7 % life • aquatic co on agricultural 16) first reason can be extensive use of fertilizers being used on agricule lands which ultimately finds it's into the weiter bodies & leading eventuall to dead zone. This occurs mainly in summer season sparking algal blooms and dead Second reason can be climate change as a result of extensive human activities detrimental te emironment. Due to climate change and unusually heavy runs more nutrients are washed t into the gulf triggering a dead zone formation. In summers there is more fresh water on top of cold salt w ater. This layering leads to poor oxygen mixing between water layers worsening a dead zone More raun fall hence increases the Seabroblems su dead zne is evident more en summers. with iner