The Oceans Surrounding Port Arthur, Texas

In today’s article, we will be discussing the oceans surrounding the town of Port Arthur, Texas.  Port Arthur is a small town on the Northeast coast of Texas. Port Arthur is approximately 90 miles (144.841 kilometers) east of Houston, & 317.1 miles (510.32298 kilometers) south of Dallas.

Port Arthur is extremely economically important to Texas, as Motiva Oil Refinery, the largest oil refinery in the U.S, is located in Port Arthur. As the town is located directly on the coast, the town is only approximately 7 feet (2.1336 meters) in elevation.

Due to this low elevation & proximity to the Gulf of Mexico, the town is extremely susceptible to hurricanes.

The town is primarily located in Jefferson County, however, it does have a small strip of land in the neighbouring Orange County. The town census-designated area is approximately 144.1 square miles (373.21729 square kilometers), 46.61% of which is covered in water.

The town's coastlines have a very high amount of marine mammals, which have been written about in the town's newsletter. These marine mammals can be seen around the port or prancing off the coast in the ocean. Port Arthur rests along the Atlantic Ocean, more specifically, the Gulf of Mexico. For this reason, the waves are milder along the Port. The beaches along the town are very nice, & are considered to be some of the most pristine in the whole state. The best beaches that the town has to offer for swimming are Macfadden Beach, McFaddin Beach, & Sea Rim State Park. For fishing & kayaking, the list vastly changes.

In this article, we will discuss the Salinity, Tides, Temperatures, Marine Geography, & Oceanic Depths of The Waters Surrounding Port Arthur, the marine ecosystems of Port Arthur, the documented marine flora & fauna of Port Arthur, & finally, how rising oceanic temperatures & ocean acidification are affecting Port Arthur. With that being said, let us delve into these Gulf Stream Waters. 

A lovely photograph of Mcfaddin Beach along the coast of Port Arthur, Texas, USA. Credit to the city,of Port Arthur.

The Salinity, Tides, Temperatures, Marine Geography, & Depth Of The Oceans Surrounding Port Arthur

Unfortunately, we could not find the Salinity measurement for the oceans directly around Port Arthur. The salinity levels of the Atlantic Ocean at any given time are between 35.5 & 34.5 parts per thousand, so it can be assumed that the Salinity around Port Arthur falls in between that. Salinity is measured in 1,000 grams of water. For every 1000 grams of water, there will be a certain number of grams that are pure salt, known as parts per thousand or practical salinity units. This is how salinity or saline level is measured.

The tidal charts of the oceans surrounding Port Arthur can be found on many different websites, a few of which are: https://tidesnear.me/tide_stations/1708, https://tidesandcurrents.noaa.gov, & https://www.tide-forecast.com. Generally, the tide is mild, rarely ever getting over 3.27 feet high. The temperatures can be found on similar websites, such as: https://seatemperature.info, https://tides4fishing.com, & https://seatemperatures.net. The average yearly oceanic temperature is approximately 23.4° Celsius (74.12 Fahrenheit). With this average, a wetsuit thickness of 3 millimeters is recommended.

As of 2025, there are no riptides that are strong enough to endanger swimmers. Beaches along the port are safe for swimming, & do not have pollution levels that are harmful to humans. Since Port Arthur rests in a lake that has a canal leading to the Atlantic Ocean, the water around the town is very shallow. The deepest aquatic point in the surrounding Port Arthur is approximately 8.2 feet (2.49936 meters) deep.

Eco-tourism is extremely common in the town, as the lakes & piers make the town popular for fishing. Additionally, many bird-watching enthusiasts enjoy the nearby nature reserve. This reserve is known as the McFaddin National Wildlife Refuge. Snorkelling & Scuba diving are not very popular in the area, however, kayaking is.

The Most Prominent Marine Ecosystems Of The Oceans Surrounding Port Arthur

Ecosystem Type No. 1: Saltwater Bayou 

The Saltwater Bayou is located farther inland, towards the western side of Port Arthur. These bayous are a kind of low-lying swamp, with slow-moving water & in certain areas, standing water. These bayous are extremely important for fish, reptiles, & marine flora. These bayous are the natural habitat for many different kinds of fish, as well as different kinds of marine flora. For this reason, it is fairly popular amongst Kayakers. These bayous are generally very shallow, only 3 to 7 feet (0.9144 meters to 2.1336 meters) deep. 

A saltwater bayou near Port Arthur, Texas, USA. Credit to the United States Fish & Wildlife Service.

Ecosystem Type No. 2: Intertidal Zones 

Intertidal zones are located along the coastline, & are very common. What defines an intertidal zone, is an area that will be exposed to air at low tide, & underwater at high-tide. These intertidal zones usually house small crustaceans, such as crabs & bivalves. These zones are the most vulnerable to human activity, due to them generally being very close to the beach. 

Ecosystem Type No. 3: Fringing Coral-Reefed Areas 

Off the coast of Port Arthur, on the Texas side, there are 3 banks of coral reefs. These banks are known as the East Flower Garden Bank, Stetson Bank, & the West Flower Garden Bank. These coral reefs are considered to be a marine sanctuary.  These coral reefs are located in the gulf itself, & are only accessible by boat. These coral reefs are known to have approximately 23 species of Coral, & 173 species of tropical fish.

In addition to these fish, over 300 species of marine molluscs & arthropods inhabit these banks. Coral reefs are extremely biodiverse, & are used as a hunting ground, shelter, spawning grounds, & breeding grounds. 

The Documented Marine Flora Of Port Arthur

Unfortunately, we have very little data on the marine flora that inhabits the saltwater marshes surrounding Port Arthur. 

The Documented Marine Fauna Of Port Arthur

Port Arthur is very biodiverse when it comes to marine fauna. For this section, we will only be discussing the marine fauna that is in the Gulf. With the warm water streams, marine mammals will often migrate here in the winter. Additionally, the coral reefs will attract many different types of tropical fish.

As said in the subsection titled “Ecosystem Type 3: Fringing Coral Reefed Areas”, the main coral reefs are located in the East Flower Garden Bank, West Flower Garden Bank, & Stetson Bank. As of 2025, there are no endemic marine species in Port Arthur. Currently, there are believed to be 173 species of fish, 300 molluscs, & at least 3 different species of whale. 

How Rising Oceanic Temperatures & Ocean Acidification Impacts The Oceans Of Port Arthur

Ocean acidification is caused by increased levels of carbon dioxide in the atmosphere.  Atmospheric carbon dioxide levels have increased, largely because of human-caused burning of fossil fuels, & deforestation, for the past 150 years.  When carbon dioxide contacts seawater, it forms carbonic acid.  Carbonic acid gives off positive hydrogen ions, which causes increased oceanic hydrogen ion concentrations & decreased oceanic pH..This off-balance pH can cause the coral around Port Arthur to become stressed out. When coral becomes stressed out, it will expel a kind of algae that is called zooxanthellae. Once the Zooxanthellae are expelled, the coral will bleach, & eventually die. Unfortunately, once the coral is already bleached, it is extremely hard for it to recover. Thankfully, the coral reefs around Port Arthur are not endangered yet, though as ocean temperatures rise, & acidification events increase, the threat of higher coral mortality grows ever higher. 

Directories / Credits

Citation No. 1: “Wetsuit thickness and temperature guide, Written by Mark Evans, & Published on April 24th, 2023, at 3:05 PM. Published By Scuba Divers Magazine. Retrieval Date: November 29th, 2023.

https://www.scubadivermag.com/wetsuit-thickness-and-temperature-guide/#Scuba_diving_wetsuits

Citation No. 2: “Flower Garden”: Marine Sanctuary Prepare To Be Amazed” Written by Unknown & Published at an Unknown Date. Published by Panama Jack.  Retrieval Date: November 30th, 2023 

https://panamajack.com/blogs/under-the-sea/flower-garden-marine-sanctuary-prepare-to-be-amazed

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