Oceans and Seas

The famous Cabo, Mexico arch is sometimes considered the delineation between Mexico’s Sea of Cortez and the Pacific Ocean. However, there is no real line that creates that distinction.

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Since we had recently been on the Caribbean Sea, I thought it would be interesting to find out the difference between an ocean and a sea. Big mistake. This turned out to be quite a complex subject, one that after hours of research I still am a little confused about. I shouldn’t feel too bad though: oceanographers make their living trying to make a seemingly simple question incredibly complex.

First, even though I am guilty of doing it, the words ocean and sea are not really interchangeable geographically. There are differences, something that I assumed. In addition, each has its own distinct features and characteristics. So, in general, and that is important because oceanographers can get very specific, oceans are much larger and not bounded by land—in fact you can say that land is bounded by them. Seas, on the other hand, are smaller and typically bounded by land on most sides. Think of the Mediterranean Sea bounded between Europe, Africa and Asia. In addition, oceans are much deeper, with an average depth of about 12,000 feet while the Mediterranean Sea, one of the world’s largest seas, has an average depth of about half that of oceans. Seas may be nearly surrounded by land, but still maintain connection to oceans.

A main question I had was, where, exactly, are the boundaries between seas and oceans and oceans and oceans? That turned out to be an interesting question. In a real sense, there is only one ocean, called the World Ocean, one continuous body of global water. Boundaries are more a conscript of humans. So, if you are looking for an exact dividing line between the Pacific and the Arctic Ocean, for instance, it does not exist on the water. The transition is over many miles and may even be dynamic (moveable) with conditions.

Globally, there are five oceans within this World Ocean. They are the Pacific, Atlantic, Indian, Southern and Arctic oceans. They are distinct, even though boundaries might not exist, and influence our world in dramatic ways. The current El Nino that is rocking our climate is a good example of how the Pacific Ocean can influence our lives.

We’ve all heard reference to “sailing the seven seas”, an ancient mariner’s phrase. What waters does it refer to? In today’s world, this phrase has no real meaning and must be taken in context with what was known about the globe anciently. At some point, the “seven seas” may have just been a reference to heading out into the unknown, but to the Greek point of view they were: the Aegean, Adriatic, Mediterranean, Black, Red, and Caspian seas, with the Persian Gulf thrown in as a "sea." Ancient Europeans had a different view of the world and the phrase referred to the North Sea, Baltic, Atlantic, Mediterranean, Black, Red, and Arabian seas. As seamen gained experience on the Atlantic, the “seven seas” likely referred to the Arctic, the Atlantic, the Indian, the Pacific, the Mediterranean, the Caribbean, and the Gulf of Mexico, a mix of seas and oceans by today’s definition.

Currently, we recognize over 50 seas worldwide. The largest of these is the Bering Sea. Each is unique as well. For instance, the Red Sea is the saltiest and the warmest sea, the coldest seas are found near the poles. The Sargasso Sea is the only sea not bounded by land, but rather by ocean currents of the Atlantic and it has dynamic borders.

What about inland seas? Inland seas are completely surrounded by land. They may have connections to the ocean via a river or strait. There are some scientists who will argue that inland waters are just really big lakes. However, inland seas have several characteristics that don’t support that philosophy. First, they are neither fresh or salt water, rather brackish water that is somewhere in between. Inland seas are shallow, none exceeding 2,000 feet in depth and most importantly in my mind, are so large that they experience tides. Hudson Bay is the world’s largest inland sea and the Baltic Sea is a distant runner-up. The Caspian Sea and Black Sea are other examples of inland seas.

Around 70 percent of this planet covered with oceans and seas. Over half of the known wildlife species in the world are marine species and scientists estimate that 91 percent of ocean species have yet to be classified. And if you are looking for unmatched adventure, more than eighty percent of our ocean is unmapped, unobserved, and unexplored. Who knows what biological treasures are just waiting to be discovered?

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Help Idaho Wildlife

When we traveled across the state in October 2017, most of the vehicles we saw using the wildlife management areas did not have wildlife plates. Buying wildlife plates is a great way for non-hunters and hunters alike to support wildlife-based recreation like birding.

C'mon folks, let's help Idaho's wildlife by proudly buying and displaying a wildlife license plate on each of our vehicles! 

See below for information on Idaho plates. Most states have wildlife plates so if you live outside Idaho, check with your state's wildlife department or vehicle licensing division for availability of state wildlife plates where you live. 

And tell them that you heard about it from Nature-track.com!

Wildlife License Plates

Great news! as of 2024, there are three NEW designs for license plates. They still are bluebird, cutthroat trout and elk, but they are beautiful.

Idaho Wildlife license plates provide essential funding that benefits the great diversity of native plants and wildlife that are not hunted, fished or trapped—over 10,000 species or 98% of Idaho’s species diversity. Game species that share the same habitats (such as elk, deer, antelope, sage-grouse, salmon, trout) also benefit from these specialty plates.

No state tax dollars are provided for wildlife diversity, conservation education and recreation programs. Neither are any revenues from the sale of hunting or fishing licenses spent on nongame species. Instead, these species depend on direct donations, federal grants, fundraising initiatives—and the Idaho Wildlife license plates.

Both my vehicles have Bluebird Plates. I prefer the bluebird because the nongame program gets 70 percent of the money from bluebird plates, but only 60 percent of the money from elk and trout plates - 10 percent of the money from elk plates supports wildlife disease monitoring and testing programs (to benefit the livestock industry) and 10 percent from cutthroat plates supports non-motorized boat access.

Incidentally, in 2014, the Idaho Legislature denied the Department of Fish and Game the ability to add new plates or even to change the name of the elk and cutthroat plates (very specific) to wildlife and fish plates, a move that would have allowed for changing images occasionally and generating more revenue. It would seem that they believe that we Idahoans don't want a well funded wildlife program.

I think it is time we let the Legislature know that Idahoan support wildlife funding and that we would like to see these generic plates come to fruition.