Contrary to what many people think, the earth's oceans are not infinite. The oceans cover 71 percent of the Earth's surface and contain 97 percent of the Earth's water. Less than 1 percent of the Earth's water is fresh water, and 2-3 percent is contained in glaciers and the North and South Pole ice caps. The oceans also contain 99 percent of the living space on the planet.
Think about that for a minute, then ponder on the following.
Oceans are by far the largest carbon sink on the planet, storing some 30 per cent of carbon dioxide and 93 per cent of all greenhouse gases. Because of increased human activity the oceans are struggling to keep up. In discussion and studies about ocean issues, the effect of greenhouse gases hasn't received nearly as much attention as ocean plastic pollution, largely because the problem is not visible. Oxygen is as essential to ocean life as it is to life on land. And while it can vary at different depths and different oceans, rising sea temperatures have caused deep ocean areas already low in oxygen, to deoxygenate further, changing habitats for underwater life.
This is not good news. There are 228,450 known species in the ocean and an estimated 2 million more that remain a total mystery to scientists and ocean biologists. Many species are likely to go extinct due to pollution, climate change and acidification before they are even found,
So the question is; what must we do as a race to protect the oceans from further degradation and species loss?
A major issue in my eyes is the cruise ship industry.  Recent data has shown that one cruise ship emits as much pollution in one day as one million cars according to German environmental study group, NABU Nature and Biodiversity Conservation Union . Their research found pollution from the cruise ship industry is still massive despite claims from the industry executives that newer vessels are clean and green. NABU carried out studies on a number of cruise lines and have proven that in nearly all cases, their attitude to the environment is still poor if not downright negligent.
"The cruise companies know what they are doing, and they know about the problems. But still, they order new ships and don't install emission abatement systems." This according to Dietmar Oeliger, the head of transportation studies at NABU.
Currently, there are 314 cruise ships in the world. It is not a great number when compared to the ocean freighters in the world's fleet now estimated at 53,045 at the end of 2018.  The big difference however between a freighter and a cruise ship is a cruise ship's engines run 24/7. In ports, they have to keep their engines running as the ship is not a transport mode, it's a hotel facility.
They have spas, restaurants, cafes, coffee bars, swimming pools, casinos, theatres and other entertainment venues that require a great of energy, more or less the same energy as a small city requires. Carnival Corporation, the world’s largest luxury cruise operator, emitted nearly 10 times more sulphur oxide (SOX) around European coasts than did all 260 million European cars in 2017. And, Carnival and its Princess subsidiary recently agreed to pay a criminal penalty of $20 million for environmental violations including dumping plastic waste into the ocean. Carnival has already paid $40 million over other deliberate acts of pollution.
There is reams and reams of material on the internet on the issue of cruise lines and pollution. Cruise ships are becoming bigger. Climate warming is now providing cruise ships with access to very eco sensitive areas as the Arctic and the Antarctic. As recently as the 1970's, cruise ships were once know as passenger ships and provided an economical means of travel from one country to another prior to airlines becoming a cost effective means of travel for the average person. Now they are floating pollution machines; 314 floating Las Vegases; a blight on both oceans and the ports they visit. Is the tourist dollars they generate worth the degradation of the earth's oceans and an entire eco-system? Just asking!