Cathechism of Catholic Chuch
2402 In the beginning God entrusted the earth and its resources to the common stewardship of mankind to take care of them, master them by labor, and enjoy their fruits. The goods of creation are destined for the whole human race. However, the earth is divided up among men to assure the security of their lives, endangered by poverty and threatened by violence. The appropriation of property is legitimate for guaranteeing the freedom and dignity of persons and for helping each of them to meet his basic needs and the needs of those in his charge. It should allow for a natural solidarity to develop between men.

The Catechism of Catholic Church 2402 states that, God created the earth and the resources for mankind to take good care of them. However, marine pollution cannot be considered as ‘taking good care of our resources’. Catholic churches oppose marine pollution that mankind should take care of ocean as it is the important resource that God created for us. The term 'stewardship' itself refurs to the takeing care of the world includeing the seas by polluting our waters we are not looking after the water so the Catholic perspective is that we should not pollute our waters and work to do the opposite.

2417 God entrusted animals to the stewardship of those whom he created in his own image. Hence it is legitimate to use animals for food and clothing. They may be domesticated to help man in his work and leisure. Medical and scientific experimentation on animals is a morally acceptable practice if it remains within reasonable limits and contributes to caring for or saving human lives.

According to the Catechism of Catholic Church 2417, mankinds are allowed to use animals for food and clothing. This can only be tolerated if it is used for his work and leisure. Also, it is acceptable if we use animals by experimenting to enhance and save human lives. However, polluting ocean to harm animals is not allowed as we have exceeded the reasonable limits.

Pastoral Letter of the Bishops of the Boston Province
"Faced with the widespread destruction of the environment, people everywhere are coming to understand that we cannot continue to use the goods of the Earth as we have in the past. . . . A new ecological awareness is beginning to emerge . . . The ecological crisis is a moral issue"
Pope John Paul II
“The Ecological Crisis: A Common Responsibility,” nos. 1, 15
December 8, 1989

Pope John Paul II is concerend about the destruction of the environment we are currently experiencing with. This includes marine pollution that we are allowed to be use the goods from ocean but we are not allowed to pollute them. As marine is God's given gift, we need to respect our marine environment and as well as other environments to preserve the good Earth and our morality as well.

Bible Passages
“God admires all that he has made and finds it good” (Gen l:3)

The Book of Genesis talks about God's creation of earth. The passage from above is about God has created all things on earth for allowing us to access the goods. The "goods" include all the things we can get from our wonderful environments. For example, ocean provides us food, leisure and other important things. We are meant to enjoy these things from our ocean, because God has given us freedom to use it for good. However, we are not meant to destroy this environment or abuse it for our own greed. Nowadays, a lot of industries are abusing marine environment to save some money or they get lazy to preserve the environment. This is a clear example of violating God's purpose for using marine environment.

Passage Genesis 1:26-28:
26 Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, [a] and over all the creatures that move along the ground."
27 So God created man in his own image,
in the image of God he created him;
male and female he created them.

28 God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground."

God has given us power to rule over the sea and other environment. However, we have to keep in mind we need to take proper care over the environment. By polluting the sea, we are actually acting against God’s teaching. God blesses all the things on earth; thus, we need to respect all living things and its environment.